I come across the Library of Congress flickr feed once in a while and it has to be one of my favorites to kill time browsing through. They have shots of our local state fair from the 40's and 50's. Awesome stuff.
Here are a few of Les Paul. They have been updating with A LOT of music stuff lately. Posted a shot of Frank Sinatra over on fb.
http://www.flickr.com/photos/library_of_congress/