Photo and Image sites

You might want to look at:

Share, Remix, Reuse — Legally
Creative Commons provides free tools that let authors, scientists, artists, and educators easily mark their creative work with the freedoms they want it to carry. You can use CC to change your copyright terms from "All Rights Reserved" to "Some Rights Reserved."

http://www.flickr.com/creativecommons/

and

The Library of Congress' photostream
http://www.flickr.com/photos/library_of_congress/

Chuck