I have long been a fan of the Library of Congress and in particular their digital initiatives. It is amazing to go and find images of rare maps or photographs.
And now, there is the Library of Congress YouTube Channell at: http://tr.youtube.com/user/LibraryOfCongress.
Here, you will find:
Timeless treasures and contemporary presentations from the Library of Congress in Washington, D.C. As the world’s preeminent reservoir of knowledge, we are the steward of millions of recordings dating from the earliest Edison films to the present. In addition, we sponsor events, lectures and concerts that are free and open to the public.
This is an excellent discovery and learning tool. I am still having fun checking out old videos!