vicinity results based on zip code

[steve3000]

does anyone know how to pull up the
nearest results to a user input
based on zip code. for example if the
user inputs a zip code my query will
search within 500 numbers of that zip
if no hits it expands to 1000. now if
i get 8 results how do i display the
four closest results to the users
input. any help greatly appreciated

[brandonschnell]

i'm interested in this also. but from what i found, most of the zip code databases are sold commercially with a sdk. the prices run about $500-$1000, but i'd be interested if anyone knows of a free zip code database.

[pnoeric]

Your wish is my command... or at least, I think you'll like this link :-)

http://www.cryptnet.net/fsp/zipdy/

From that page--

"Zipdy is a program for calculating the distance between two zip codes and finding all the records in a RDBMS with a zip code with x miles of another zip code. ... Zipdy is free software released under the terms of the GNU General Public License. Zipdy was written in C but is also available in PHP and perl. It runs with data from the US Census Gazetteer program. The original Gazetteer data is available here. The data is a little old (from the 1990 census) and there for not complete for newer zip codes in some rural areas, but I've found it to have nearly every zip code I checked. If you know of a source for a newer data file, please let me know."

enjoy...
-Eric

[Anon]

try this, I just ran across it

http://www.cfdynamics.com/zipbase/