The Prelinger Archives

Quite possibly the best American film collection ever. An absolutely heroic one-man effort, now well situated with the Library of Congress, with selections via the Internet Archive:

http://www.prelinger.com

http://www.loc.gov/rr/mopic/

http://www.archive.org/details/prelinger

Link to/discuss favorites here.

On a related note, there's the Texas Archive of the Moving Image under the direction of the amaaaaazing Caroline Frick. You must check out the fascinating story of Melton Barker, a Dallas “itinerant filmmaker” who starting in the 1930s shot sync sound Little Rascals-style films with local children in various locations in the US. More info here:

http://www.texasarchive.org/collections/barker.htm

Nice, thanks for that!