Zip Codes Lookup
For ZIP code and Zip+4 lookups, you can’t beat the efficiency of the good old United States Postal Service (U.S.P.S.)
Your tax dollars at work have created a very user-friendly interface to reverse lookup a street address to find the ZIP code associated with it. You can even find all zip codes in a city, or search for a zip code by a company name.
This company provides zip code lookup information with demographics targeted towards direct marketers who need mailing addresses.