I'm designing an auction website and I want to have a drop-down list box that automatically populates with all the provinces/states/territories from a selected country. I also want to replicate an eBay feature that lets buyers type in their postal or zip code and search for sellers within a certain distance. Are there any public domain databases that I could download or any mash-ups I could use to help me do this? I'm hoping I don't have to collect this data manually...

I have done a similar search in the past and found that public domain db's for zip code data are simply not available [or that I could find] however there are some packages available for as little of fifty dollars. I am heading out now, but will take a look later to see if I can relocate the one I had found [but did not buy as the project got canceled].

If anyone else discovers a mash-up or freely available db for this please do reply to this thread - this would be an excellent resource for many folks.

I found these downloadable databases:
http://www.zipcodedownload.com/
http://www.zip-codes.com/

They have both US and Canadian data and calculate distances between different zip codes and postal codes. But they can set you back a few hundred bucks depending on the package you buy.


I've also found a few projects on sourceforge.net:
http://sourceforge.net/projects/zipcodefinder/
http://sourceforge.net/projects/zipdy/
http://sourceforge.net/projects/zips/

They let you calculate distances but they are only for the US. I'm looking for something worldwide.