I was interested in a project for a website as to what data could be retrieved from PetFinder.com. To my surprise, on their website located in the footer is a link to their API documentation. In order to use their API, you must first fill out a developer request for a key & password. I did a quick look to see if anyone had written a php class for accessing the api, but couldn’t find anything useful. I have created a php class that you can call the certain methods available to retrieve the records.
Update 6-30-2010:
I recently updated the class to enable caching the xml response from the Petfinder server. This should provide a nice little speed boost even though it was already pretty fast :). Caching is enabled by default, and caches expires in 3 minutes. The folder “cache_files” in zip folder must have write permissions. As shown in the instructions, you can change the paths of cache files.