Simple CC flickr Search is a Great link for photos. Basically this site searches flickr for Creative Commons photos. The cool part comes when you click on a photo it gives you the embed code with the appropriate Creative Commons Attribution. So this is what appears on your blog, site or where ever you choose to use the photo.
Photo by jakebouma
Very cool you now don’t have to worry about attributes on flickr photos!!
As a bonus you can edit in picnik right from the site.