I've pointed to the Everything is a Remix series previously; it's a series of short documentaries by Kirby Ferguson, discussing how newly created work (music, movies, etc.) is influenced by existing work -- and ultimately, how our systems of copyright and patents aren't built to deal with this. (SOPA/PIPA opponents, you might want to watch this.)
In this fourth and final part of the series, Ferguson talks about artistic creation as a form of social evolution...and the history of copyright and patents.... READ ON