This is a cool greasemonkey script to generate attribution for CC images on Flickr. Works as an embed - would be good to tweak and have a plain text attribution including the CC variant details.
PicFindr searches the web* for stock photography that is completely free to use commercially. Several licensing arrangements have recently emerged as alternatives to copyright (sometimes called "copyleft") and PicFindr makes sense of them all by helping you find images based on what you have to do to use them, whether licensed under Creative Commons, GNU, a site-specific agreement, or something else. PicFindr can even find free images you can use commercially without requiring permission or credit of any kind!