Seriously, there are at least two documentaries about Live Action Role Playing.
Darkon: The Movie follows folks from The Darkon Wargaming Club, a SCA-like group that conducts fantasy based games. They’ve even put up links to a PDF version of their >200 page rulebook here.
Darkon: The Movie is probably benefitting greatly from the fact that its Amazon.Com product page incorrectly list George Clooney as appearing in the film.
Monster Camp (warning, completely POS Flash-based navigation) is scheduled for release on DVD in September. It follows folks participating in a New England Role Playing Organization LARP in Seattle, Washington.