great resource for stock photos

Hi all -
I just found a pretty cool resource for searching and downloading (free) good-quality photos-- Flickr has teamed up with Library of Congress, the Smithsonian, and other big museums to put their copyright-free picture online! You can search and download at will, and not worry about stepping on any copyright toes:

http://www.flickr.com/commons/

When you see a photo you like, click on the little "all sizes" button directly above the photo and you can download it. I'm not sure if you have to be a flickr member to do it, though.