If you like vintage photos than The Commons could be worth a click.

It is a pilot project of the U.S. Library of Congress. They digitized images from their collections that have no known copyright restrictions and uploaded them to flickr.com.

With the help of the community they hope to increase the value of this collection. By adding tags and comments the users should make it better search- and reusable and add supplementary information.

There are two sets available:

• “News in the 1910s”: black-and-white photos of the Bain News Service.
• “1930s-40s in Color”: color photos taken by the Farm Security Administration and the Office of War Information.

Even though the description may not sound so interesting, the images are really worth taking a look.

for more information:
“Flickr Takes Historical Imagery To The Masses” at TechCrunch.com
“My Friend Flickr: A Match Made in Photo Heaven” at the Library of Congress Blog

There is a similar approach of the National Library of Australia, which is available at Picture Australia.

Update: To be able to view the gallery you need Flash. Windows and Mac users can download it from Adobe’s Web site [English|Deutsch]. If Ubuntu users might need help: Take a look at ubuntuguide.org and search for “Flash”. Normally a

sudo apt-get install flashplugin-nonfree

should do it.