Drupal for domestic pet shelters and rescue

I recently created a web site for lost, found, and adoption notices for domestic pets. The goal is to assist the general public as well as shelters and rescues. In my area the main way to rehome a pet by private individual is a Craigslist posting, which is inefficient. I am not affiliated with any other animal welfare group.

There is one discussion on Petfinder integration. http://drupal.org/node/240993

One problem I have is proximity search, such as each pet is a node, and users search for nodes by distance. I figured out the Location module, but I think, though am not sure, other modules such as Geo and Openlayers do not require the maintenance of the zip code database. I have searched diligently for a tutorial and have found nothing I can successfully follow.

If you have any insight into proximity searching, please respond.

I am relatively new to Drupal so welcome anyone who has something to offer.

My web site is www.missingpups.com It is being upgraded continuously.

Thanks.