CinemaTech has an interesting, brief note about a "remixable movie." Kind of the antithesis (not a bad thing) of the "self-reliant film", a filmmaker is posting her all her footage and letting anyone that wants to take a crack at editing it. Could be a desperate gimmick for attention, could be really great... I'll have to find out more. Reading about it made me think of a few other projects that attempted something like this (say, the now-defunct Madstone Films' Rhinoceros Eyes">Rhinoceros Eyes). Probably the most exciting approach was taken by the filmmakers of the conspiracy-pseduo-mock-documentary Nothing So Strange. The film concerns the 1999 assassination of Bill Gates. (Hey, I said it was a conspiracy film.) In addition to the filmmakers' "official release", they also released their footage to people that would like to take a crack at editing it themselves. "Open Source Filmmaking" was what they called it -- a brilliant concept to apply to a film about the big daddy of closed-source computing. You can read more about the open source initiative (and download footage) here.
The flip side of this approach, of course, is public-domain (aka found-footage) filmmaking -- that is, making films with footage from public (or not-so-public) domain archival film. For the uninitiated, Bruce Conner and Jay Rosenblatt are masters of the form. The as-darkly-funny-as-Dr. Strangelove Atomic Cafe is also, I think, required viewing.
If you want to get in on the action, check out Archive.org where you can download movies to watch and, well, make movies with.