UNITED STATES
               SECURITIES AND EXCHANGE COMMISSION
                     Washington, D.C. 20549

         _______________________________________________

                          SCHEDULE 13D

            Under the Securities Exchange Act of 1934

                        SWITCHBOARD, INC.
                        (Name of Issuer)

             Common Stock, Par Value $.01 per share
                 (Title of Class of Securities)

                           871045-10-0
                         (CUSIP Number)

                       Sumner M. Redstone
                    National Amusements, Inc.
                         200 Elm Street
                   Dedham, Massachusetts 02026
                    Telephone: (781) 461-1600

                         with a copy to:

                    Michael D. Fricklas, Esq.
                           Viacom Inc.
                          1515 Broadway
                    New York, New York 10036
                    Telephone: (212) 258-6000
             (Name, Address and Telephone Number of
    Person Authorized to Receive Notices and Communications)

                           May 4, 2000
     (Date of Event which Requires Filing of this Statement)


    _________________________________________________________

If the filing person has previously filed a statement on Schedule
13G to report the acquisition which is the subject of this
Schedule 13D, and is filing this schedule because of Rule 13d-
1(b)(3) or (4), check the following box / /.

Check the following box if a fee is being paid with this
statement / /.










CUSIP No. 871045-10-0 (1) Name of Reporting Person S.S. or I.R.S. Identification No. of Above Person SUMNER M. REDSTONE S.S. No. - --------------------------------------------------------- (2) Check the Appropriate Box if a Member of Group (See Instructions) / / (a) - --------------------------------------------------------- / / (b) - --------------------------------------------------------- (3) SEC Use Only - --------------------------------------------------------- (4) Sources of Funds (See Instructions) N/A - --------------------------------------------------------- (5) Check if Disclosure of Legal Proceedings is Required Pursuant to Items 2(d) or 2(e). - --------------------------------------------------------- (6) Citizenship or Place of Organization United States - --------------------------------------------------------- Number of (7) Sole Voting Power Shares --------------------------------- Beneficially (8) Shared Voting Power 8,555,497* Owned by -------------------------------- Each (9) Sole Dispositive Power Reporting -------------------------------- Person (10) Shared Dispositive Power 8,555,497* With - --------------------------------------------------------- (11) Aggregate Amount Beneficially Owned by Each Reporting 8,555,497 - --------------------------------------------------------- (12) Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions) - --------------------------------------------------------- (13) Percent of Class Represented by Amount in Row (11) 36%* - --------------------------------------------------------- (14) Type of Reporting Person (See Instructions) IN - --------------------------------------------------------- * Includes 1,066,937 shares underlying currently exercisable warrants.

CUSIP No. 871045-10-0 (1) Name of Reporting Person S.S. or I.R.S. Identification No. of Above Person VIACOM INC. I.R.S No. 04-2949533 - --------------------------------------------------------- (2) Check the Appropriate Box if a Member of Group (See Instructions) / / (a) - --------------------------------------------------------- / / (b) - --------------------------------------------------------- (3) SEC Use Only - --------------------------------------------------------- (4) Sources of Funds (See Instructions) N/A - --------------------------------------------------------- (5) Check if Disclosure of Legal Proceedings is Required Pursuant to Items 2(d) or 2(e). - --------------------------------------------------------- (6) Citizenship or Place of Organization Delaware - --------------------------------------------------------- Number of (7) Sole Voting Power Shares --------------------------------- Beneficially (8) Shared Voting Power 8,555,497* Owned by --------------------------------- Each (9) Sole Dispositive Power Reporting --------------------------------- Person (10) Shared Dispositive Power 8,555,497* With - --------------------------------------------------------- (11) Aggregate Amount Beneficially Owned by Each Reporting 8,555,497* - --------------------------------------------------------- (12) Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions) - --------------------------------------------------------- (13) Percent of Class Represented by Amount in Row (11) 36% - --------------------------------------------------------- (14) Type of Reporting Person (See Instructions) CO - --------------------------------------------------------- * Includes 1,066,937 shares underlying currently exercisable warrants.

Item 1. Security and Issuer. --------------------- The class of equity securities to which this Statement on Schedule 13D relates is the Common Stock, $.01 par value per share (the "Common Shares"), of Switchboard, Inc. (the "Issuer"), a Delaware corporation, with its principal executive office located at 115 Flanders Road, Westboro, Massachusetts 01581. Item 2. Identity and Background. ------------------------ This Statement is filed by Mr. Sumner M. Redstone, National Amusements, Inc. ("NAI"), NAIRI, Inc. ("NAIRI"), and Viacom Inc. ("Viacom") (collectively, the "Reporting Persons"). Viacom, a Delaware corporation, has its principal executive offices at 1515 Broadway, New York, New York 10036 and is a diversified entertainment and communications company. At May 12, 2000, approximately 68% of Viacom's voting Class A Common Stock, par value $.01 per share, and approximately 13% (on a combined basis) of Viacom's Class A Common Stock and non-voting Class B Common Stock, par value $.01 per share, was owned by NAIRI. NAIRI, a Rhode Island corporation, has its principal office at 200 Elm Street, Dedham, Massachusetts 02026 and is a company owning and operating movie theaters in the United States whose main asset is its shares of Viacom Class A Common Stock and Class B Common Stock. NAI, a Maryland corporation, has its principal office at 200 Elm Street, Dedham, Massachusetts 02026. NAI's principal businesses are owning and operating movie theaters in the United States, United Kingdom and South America and holding the common stock of NAIRI. 66-2/3% of the issued and outstanding shares of capital stock of NAI are beneficially owned by Mr. Sumner M. Redstone, as trustee of a trust owning such shares. Sumner M. Redstone is an individual whose business address is c/o National Amusements, Inc., 200 Elm Street, Dedham, Massachusetts 02026. Mr. Redstone's principal occupation is Chairman of the Board and Chief Executive Officer of NAI, Chairman and President of NAIRI, and Chairman of the Board and Chief Executive Officer of Viacom Inc. The executive officers and directors of Viacom, NAIRI and NAI are set forth on Schedules I through III attached hereto, containing the following information with respect to each such person: (a) Name; (b) Residence or business address; and (c) Present principal occupation or employment and the name, principal business and address of any corporation or other organization in which such employment is conducted. During the last five years, neither of the Reporting Persons nor any person named in any of Schedules I through III attached hereto has been (a) convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors) or (b) a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws. Except for Jan Leschly, who is a Danish citizen, all of the directors of Viacom, NAIRI and NAI, including Mr. Sumner M. Redstone, are citizens of the United States.

Item 3. Source and Amount of Funds or Other Consideration. The Issuer's Common Shares were acquired by the Reporting Persons pursuant to the merger of CBS Corporation ("CBS"), immediate prior owner of the Common Shares and Special Preferred Stock (as defined in Item 5 below), with and into Viacom on May 4, 2000. Item 4. Purpose of Transaction. The Issuer's Common Shares were acquired by the Reporting Persons pursuant to the merger of CBS, immediate prior owner of the Common Shares and Special Preferred Stock, with and into Viacom on May 4, 2000. The Reporting Persons may, at any time and from time to time, purchase additional Common Shares of the Issuer and may dispose of any and all Common Shares of the Issuer held by them. Notwithstanding the foregoing, the Reporting Persons have no current plan or proposal which relates to, or would result in, any of the actions enumerated in subparagraphs (a) through (j) of Item 4 of Schedule 13D. Item 5. Interest in Securities of the Issuer. (a) and (b) Viacom is currently the beneficial owner, with shared dispositive and voting power, of 8,555,497 Common Shares, including 1,066,937 Common Shares underlying currently exercisable warrants (the "Subject Warrants"), and one share of Series E Special Voting Preferred Stock (the "Special Preferred Stock") or approximately 36%, of the Issuer's issued and outstanding Common Shares (based on the number of Common Shares that were reported by the Issuer to be issued and outstanding and assuming the exercise of all the Subject Warrants and such underlying shares to be issued and outstanding for purposes of this calculation). NAIRI is currently the beneficial owner, with shared dispositive and voting power, of 8,555,497 Common Shares, including 1,066,937 Common Shares underlying the Subject Warrants, and the Special Preferred Stock or approximately 36%, of the Issuer's issued and outstanding Common Shares (based on the number of Common Shares that were reported by the Issuer to be issued and outstanding and assuming the exercise of all the Subject Warrants and such underlying shares to be issued and outstanding for purposes of this calculation). NAI is currently the beneficial owner, with shared dispositive and voting power, of 8,555,497 Common Shares, including 1,066,937 Common Shares underlying the Subject Warrants and the Special Preferred Stock or approximately 36%, of the Issuer's issued and outstanding Common Shares (based on the number of Common Shares that were reported by the Issuer to be issued and outstanding and assuming the exercise of all the Subject Warrants and such underlying shares to be issued and outstanding for purposes of this calculation). As a result of his stock ownership in NAI, Mr. Sumner M. Redstone is deemed the beneficial owner of 8,555,497 Common Shares, including 1,066,937 Common Shares underlying the Subject Warrants, and the Special Preferred Stock or approximately 36% of the issued and outstanding Common Shares (based on the number of Common Shares that were reported by the Issuer to be issued and outstanding and assuming the exercise of all the Subject Warrants and such underlying shares to be issued and outstanding for purposes of this calculation).

(c) The Issuer's Common Shares and Special Preferred Stock were acquired by the Reporting Persons pursuant to the merger of CBS, immediate prior owner of the Common Shares and Special Preferred Stock, with and into Viacom on May 4, 2000. (d) None. (e) N/A Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer. None of the Reporting Persons have entered into, or amended any existing, agreement with respect to the Common Shares or other securities of the Issuer since the prior statement on Schedule 13D, or amendment thereto, that was filed by certain of the Reporting Persons or any predecessor thereof. Viacom, as successor by merger to CBS, has assumed all rights and obligations of CBS.

Signatures After reasonable inquiry and to the best of our knowledge and belief, we certify that the information set forth in this statement is true, complete and correct. Pursuant to Rule 13d- 1(f)(1), each of the undersigned agrees that this statement is filed on behalf of each of us. May 15, 2000 /s/ Sumner M. Redstone Sumner M. Redstone, Individually National Amusements, Inc. By: /s/ Sumner M. Redstone -------------------------- Sumner M. Redstone, Chairman and Chief Executive Officer NAIRI, Inc. By: /s/ Sumner M. Redstone --------------------------- Sumner M. Redstone, Chairman and President Viacom Inc. By: /s/Michael D. Fricklas --------------------------- Michael D. Fricklas Senior Vice President, General Counsel and Secretary

SCHEDULE I VIACOM INC. - ---------------------------------------------------------------------- EXECUTIVE OFFICERS - ---------------------------------------------------------------------- Name and Address of Corporation Business or Principal Occupation or Other Name Residence Address or Employment Organization in Which Employed - ---------------------------------------------------------------------- Sumner M. Viacom Inc. Chairman of the Board National Redstone* 1515 Broadway and Chief Executive Amusements, Inc. New York, NY Officer of Viacom 200 Elm Street 10036 Inc.; Chairman of the Dedham, MA Board and Chief 02026 Executive Officer of National Amusements, Inc.; President and Chief Executive Officer of Viacom International Inc. - ---------------------------------------------------------------------- Mel Viacom Inc. President and Chief Chairman, Karmazin* 1515 Broadway Operating Officer President and New York, NY Viacom Inc. and Chief Executive 10036 Viacom International Officer of Inc. Infinity Broadcasting Corporation - ---------------------------------------------------------------------- Michael Viacom Inc. Sr. VP, General Viacom D. 1515 Broadway Counsel and Secretary International Fricklas New York, NY of Viacom Inc. and of Inc. 10036 Viacom International 1515 Broadway Inc. New York, NY 10036 - ---------------------------------------------------------------------- Susan C. Viacom Inc. Vice President, Viacom Gordon 1515 Broadway Controller, Chief International New York, NY Accounting Officer of Inc. 10036 Viacom Inc. and 1515 Broadway Viacom International New York, NY Inc. 10036 - ---------------------------------------------------------------------- William Viacom Inc. Sr. VP, Human Viacom A. Roskin 1515 Broadway Resources and International New York, NY Administration of Inc. 10036 Viacom Inc. and 1515 Broadway Viacom International New York, NY Inc. 10036 - --------------------------------------------------------------------- Fredric Viacom Inc. Sr. VP, Chief Viacom Reynolds 1515 Broadway Financial Officer of International New York, NY 10 Viacom Inc. and Inc. Viacom International 1515 Broadway Inc. New York, NY 10036 - ---------------------------------------------------------------------- *Also a Director SCHEDULE I (continued) - ---------------------------------------------------------------------- DIRECTORS - ---------------------------------------------------------------------- George S. Winer & Abrams Attorney Winer & Abrams Abrams 60 State Street 60 State Street Boston, MA 02109 Boston, MA 02109 - ---------------------------------------------------------------------- George H. AKAMI Chairman and Chief Conrades Technologies Executive Officer of 201 Broadway AKAMI Technologies Cambridge, MA 02139 - ---------------------------------------------------------------------- Philippe 121 East 65th Director of Viacom P. Dauman Street Inc. and National New York, NY Amusements, Inc. 10021 - ---------------------------------------------------------------------- Thomas E. 243 Cleft Road Director of Viacom Dooley Mill Neck, NY Inc. 11937 - ---------------------------------------------------------------------- William H. UNCF President and Chief Gray III 8260 Willow Oaks Executive Officer of Corporate Drive The Fairfax, VA College Fund/UNCF 22031 - ---------------------------------------------------------------------- Jan SmithKline Chief Executive Leschly Beecham (Retired) of P.O. Box 7929 SmithKline Beecham Philadelphia, PA 19101 - ---------------------------------------------------------------------- David T. Orion Safety Chairman and Chief McLaughlin Products Executive Officer of P.O. Box 2047 Orion Safety Products Easton, MD 21601 - ---------------------------------------------------------------------- Ken Miller Credit Suisse Vice Chairman of C.S. Credit Suisse First Boston First Boston First Boston Corporation Corporation 11 Madison 11 Madison Avenue - 22nd Avenue 22nd Floor Floor New York, NY New York, NY 10010 10010 - ---------------------------------------------------------------------- Leslie Viacom Inc. President and Chief CBS Television Moonves 1515 Broadway Executive Officer of 7800 Beverly New York, NY CBS Television Blvd. 10036 Los Angeles, CA 90036 - ---------------------------------------------------------------------- Brent D. c/o Showtime Director of National National Redstone Networks Inc. Amusements, Inc. Amusements, 1633 Broadway Inc. New York, NY 200 Elm Street 10019 Dedham, MA - ---------------------------------------------------------------------- 02026 Shari National President of National National Redstone Amusements, Inc. Amusements, Inc. Amusements, 200 Elm Street Inc. Dedham, MA 02026 200 Elm Street Dedham, MA 02026 - ---------------------------------------------------------------------- Fredric V. Bell Atlantic Vice Chairman-- Bell Atlantic Salerno Corporation Finance and Business Corporation 1095 Avenue of Development of Bell 1095 Avenue of the Americas Atlantic the Americas New York, NY New York, NY 10036 10036 - ---------------------------------------------------------------------- William Yeshiva VP for Academic Yeshiva Schwartz University Affairs (chief University 2495 Amsterdam academic officer) of 2495 Amsterdam Avenue Yeshiva University Avenue New York, NY New York, NY 10033 10033 - ---------------------------------------------------------------------- Ivan Bell Atlantic Chairman of the Board Bell Atlantic Seidenberg Corporation and Chief Executive Corporation 1095 Avenue of Officer of Bell 1095 Avenue of the Americas Atlantic the Americas New York, NY New York, NY 10036 10036 - ---------------------------------------------------------------------- Patty Bill and Melinda Co-Chair and Stonesifer Gates President of Foundation Bill and Melinda 1551 Eastlake Gates Foundation Ave. East Seattle, WA 98102 - ---------------------------------------------------------------------- Robert D. Cardinal Health, Chairman and Chief Walter Inc. Executive Officer of 7000 Cardinal Cardinal Health, Inc. Place Dublin, OH 43017 - ---------------------------------------------------------------------- >PAGE> SCHEDULE II NAIRI, INC. - ---------------------------------------------------------------------- EXECUTIVE OFFICERS - ---------------------------------------------------------------------- Name and Address of Corporation Business or Principal Occupation or Name Residence Address or Employment Other Organization in which Employed - ---------------------------------------------------------------------- Sumner M. Viacom Inc. Chairman of the Board National Redstone* 1515 Broadway of Viacom Inc.; Amusements, Inc. New York, NY Chairman of the Board 200 Elm Street 10036 and Chief Executive Dedham, MA Officer of National 02026 Amusements, Inc.; Chairman and President of NAIRI, Inc. - ---------------------------------------------------------------------- Shari National President of National National Redstone* Amusements, Inc. Amusements, Inc. and Amusements, Inc. 200 Elm Street Executive Vice 200 Elm Street Dedham, MA 02026 President of NAIRI, Dedham, MA Inc. 02026 - ---------------------------------------------------------------------- Jerome National Vice President and National Magner Amusements, Inc. Treasurer of National Amusements, Inc. 200 Elm Street Amusements, Inc. and 200 Elm Street Dedham, MA 02026 NAIRI, Inc. Dedham, MA 02026 - ---------------------------------------------------------------------- Richard National Vice President of National Sherman Amusements, Inc. National Amusements, Amusements, Inc. 200 Elm Street Inc. and NAIRI, Inc. 200 Elm Street Dedham, MA 02026 Dedham, MA 02026 - ---------------------------------------------------------------------- *Also a Director SCHEDULE III NATIONAL AMUSEMENTS, INC. - ---------------------------------------------------------------------- EXECUTIVE OFFICERS - ---------------------------------------------------------------------- Name and Address Business or Principal Occupation of Corporation Name Residence Address or Employment or Other Organization in which Employed - ---------------------------------------------------------------------- Sumner M. Viacom Inc. Chairman of the Board National Redstone* 1515 Broadway of Viacom Inc.; Amusements, New York, NY Chairman of the Board Inc. l0036 and Chief Executive 200 Elm Street Officer of National Dedham, MA Amusements, Inc.; 02026 Chairman and President of NAIRI, Inc. - ---------------------------------------------------------------------- Shari National President of National National Redstone* Amusements, Inc. Amusements, Inc. and Amusements, 200 Elm Street Executive Vice Inc. Dedham, MA 02026 President of NAIRI, 200 Elm Street Inc. Dedham, MA 02026 - ---------------------------------------------------------------------- Jerome National VP and Treasurer of National Magner Amusements, Inc. National Amusements, Amusements, 200 Elm Street Inc., and NAIRI, Inc. Inc. Dedham, MA 02026 200 Elm Street Dedham, MA 02026 - ---------------------------------------------------------------------- Richard National Vice President of National Sherman Amusements, Inc. National Amusements, Amusements, 200 Elm Street Inc. and NAIRI, Inc. Inc. Dedham, MA 02026 200 Elm Street Dedham, MA 02026 - ---------------------------------------------------------------------- *Also a Director - ---------------------------------------------------------------------- DIRECTORS - ---------------------------------------------------------------------- George S. Winer & Abrams Attorney Winer & Abrams Abrams 60 State Street 60 State Street Boston, MA 02109 Boston, MA 02109 - ---------------------------------------------------------------------- David Lourie and Cutler Attorney Lourie and Andelman 60 State Street Cutler Boston, MA 02109 60 State Street Boston, MA 02109 - ---------------------------------------------------------------------- Philippe Residence: Director of National P. Dauman 121 East 65th Amusement, Inc. and Street Viacom Inc. New York, NY 10021 - ---------------------------------------------------------------------- Brent D. c/o Showtime Director of National National Redstone Networks Inc. Amusements, Inc. Amusements, Inc. 1633 Broadway 200 Elm Street New York, NY Dedham, MA 10019 02026 - ----------------------------------------------------------------------