The Library of Congress has begun putting portions of its vast audio and video collections on YouTube. So far there are fewer than 100 videos–an eclectic collection including Thomas Edison kinetoscopic movies, oral histories of Pearl Harbor, and a documentary on the poetry of Langston Hughes. But the potential certainly exists for this to be a terrific teaching resource.
The Library of Congress also makes historic photographs available on Flickr. Good stuff.
Assuming, of course, that teachers are able to access youtube in the classroom (or to download youtube videos before class).
How wonderful! And don’t forget their online connection to millions of primary sources: http://memory.loc.gov/learn/