AnyWho
Find phone numbers and addresses for business and people in the United States. Maintained by AT&T.

Area Code Finder
Input a city and state to find an area code. Also features a reverse lookup.

Area Code Maps
Click on a state to see a geographic breakdown of area codes.

Expatriates & Travelers Telephone Search Engine
A quick way to find dialing codes, directories, and foreign embassies.

International Telephone Directories
The Infobel directory of links to online telephone directories for countries around the world.

The Internet 800 Directory
Search for toll-free numbers in the United States.

Reference USA (In-Library use only)
Reference USA (Access from home or work; Belvedere & Tiburon residents only)
Directory information on U.S. businesses and residences.

Reverse Telephone Number Lookup
Input a telephone number and area code to find the address of a person or business. Many phone numbers will return no result. Use dashes to separate number.

SMARTpages.com
White pages and yellow pages from SBC.

Switchboard
Online white pages and yellow pages for the United States.

Zip Code Lookup
Find the ZIP + 4 code for any U.S. address.