If you haven't seen this, you should. It's a collection of several thousand "ephemeral films": public service announcements, commercials, documentaries, etc. In most, unintentional humor is the main draw: the blunt & clunky propaganda of 1950s Cold War films (Duck & Cover), the pipe-smokin' J.R. "Bob" Dobbs-style sex ed (from As Boys Grow: "this was all pretty new to Bill, this business of 'nocturnal emissions'"), the horrifying racial caricatures from WWII cartoons. But some of it is just fascinating, like a pair of films in which some guy filmed a fourteen-minute trolley ride down Market Street in 1905 San Francisco, then retraced his route immediately after the earthquake (think smoking ruins).
I haven't had the patience to explore this vast archive beyond the stuff on the main page, so please do so, and tell me what's good. Try to ignore the inane comments below each movie.