Web ZIP Codes -- William Murphy <tordan@cs.umb.edu> writes:

When I read the article on ProPhone, I chased the link to TidBITS-267 to see what had been said about ZIP code programs, and I thought it might be worth pointing out that the U.S. Postal Service now has its own Web server.

http://www.usps.gov/

One of the services that they offer is a ZIP+4 lookup. If all you need is the ZIP code for an address, this page is for you. Get it right from the source, and best of all, it's free.

[Even better, as far as my pet peeves go, this Web site appears to have full U.S. postal rate information, something that has been driving me nuts ever since the rates changed in January 1995. -Adam]