The Library of Congress recently posted over 3000 photos on Flickr. This is a terrific idea to make their archives more available to the public, but if I'm Flickr's hardware guy I'm probably a bit worried about storage space if they decide to post everything.
In reality, of course, the LOC will probably not be able to post all of their photos, but in the meantime we can enjoy what they have put up there and hope for more to come. They started out with two sets: 1930s-40s in Color and News in the 1910s.
I'm no photo critic and can't editorialize too much about the photos, but I do think the sets are fantastic. Maybe not each individual photo, but taken as a whole they are a fascinating snapshot of life in pre-WWII (and pre-WWI) America. They are of amazing quality, and to see color photos from that time is a treat.
If you are a photo or history buff, be sure to bookmark the LOC's Flickr page.