
The Library of Congress is putting a million public domain images on Flickr, and they need your help:
The key goals of this pilot project are to firstly give you a taste of the hidden treasures in the huge Library of Congress collection, and secondly to show how your input of a tag or two can make the collection even richer. You're invited to help describe photographs in the Library of Congress' collection on Flickr, by adding tags or leaving comments. (Via Drawn!)
Here's a link to the Library's Prints & Photographs Online Catalog-- they're not all in the public domain, but would be great for sparking story ideas or as photo-reference for illustrations, no?