If that sounds familiar, have we got a site for you. Photo Pin, an application developed by Markus Urban, uses the Flickr API to search Creative Commons licensed photos, and breaks them out between those for commercial and those for non-commercial use.
Photo Pin users are essentially searching Flickr topics using the Photo Pin search facility, can preview the photo and even click "get photo" (which provides code snippets) to download the photo which includes the proper attribution link. Photos can even be purchased when necessary. The paid results take users to fotolia to buy photos, but the free Creative Commons results from Photo Pin (which actually works way, way better than Creative Commons itself for searching Flickr photos) is going to be the way to go for a vast majority of users.