Library of Congress partners with Flickr!
From LOC's blog: The project is beginning somewhat modestly, but we hope to learn a lot from it. Out of some 14 million prints, photographs and other visual materials at the Library of Congress, more than 3,000 photos from two of our most popular collections are being made available on our new Flickr page, to include only images for which no copyright restrictions are known to exist.

The real magic comes when the power of the Flickr community takes over.