Please enter any valid US zip code. Notice the available drop down menu after a slight delay in loading on partial zip codes or full 5-digit zip codes.
The java script and zip code data is available for free for non-commercial purposes. A commercial license is available for a one-time fee of $40. This entitles you to use by a single organization, you may not resell or relicense this product to others.
The data backend for this can be downloaded via http://static.50projects.com/zips.20100809.tgz. Quick documentation is available at http://zip.50projects.com/Zip_Documentation.txt. Questions, comments or thoughts can be addressed to firstname.lastname@example.org and you'll get a response back shortly.