Ready Reference: Phone Numbers & Zip Codes

Note: Internet phone directories are usually derived from print phone directories; therefore, they are sometimes out of date.

AnyWho Toll-Free Directory: Search or browse by category AT&T's toll-free 800 and 888 phone directory.
Country and City Telephone Codes: A listing of various telephone codes for countries and cities around the world.
Expatriates Telephone Search Engine: This search engine gives calling codes instruction for other nations.
How to Call Abroad: This website gives instructions on how to dial abroad as well as country codes and current local time zone information for that country.
InfoSpace: Find over 112 million U.S. listings of people and businesses.
Phonebook of the World
Switchboard--Nationwide residential and business directory.: Find a Person | Find a Business
Teldir: Links to online telephone and business directories from around the world.
WorldPages: Direct access to 112 million U.S. and Canadian white and yellow pages listings, 9 million e-mail addresses, 30 million URLs, and links to over 200 directories worldwide.

Anywho Reverse Lookup
Reverse Phone Directory
InfoSpace Reverse Lookup
Yahoo People: This site has a reverse phone directory as well as a way to look up names and addresses.

Canadian Postal Code Lookup
City State/Zip Code Associations: Find out what cities and ZIP Codes are associated with each other. From the U.S. Postal Service.
U.S. Postal Service ZIP+4 Lookup: Find the ZIP+4 code to include in the address of your next letter. From the U.S. Postal Service.
Mailing Internationally from the US