Are there any client-side tools that allow you to autofill someone's city and state in an HTML form based on their Zip Code?

Question

Are there any client-side tools that allow you to autofill someone's city and state in an HTML form based on their Zip Code

Answer 1

Ziptastic will solve your problem http://daspecster.github.com/ziptastic/

For example, zip.elevenbasetwo.com/?zip=10001 responds with {"country": "US", "state": "NY", "city": "NEW YORK"}