Nerdcore For Life is a forthcoming documentary on nerdcore rappers -- rappers who rhyme about computers, comic books, video games, D&D, and so forth. My all-time fave is MC Chris, but there are plenty of amazing nerdcoreists, from MC++ to Lords of the Rhymes. The trailer has just been posted, and it features many talented geek rappers explaining the impetus behind nerdcoredom. Link (Thanks, Nundu!)
Update: MC Frontalot sez, "there is another Nerdcore documentary feature (trailer) coming out. It is called Nerdcore Rising, from Vaguely Qualified in NY. There's a preview trailer online which focuses on me & my touring -- but as I understand it the movie has interviews with a bunch of the same artists as Nerdcore For Life."