Just watched a fantastic documentary called 'The Dungeon Masters' following 2 male and 1 female GM's / Gamers through a year in their life during 2006 in America..
If you use lovefilm, it can be streamed for free here (http://www.lovefilm.com/film/The-Dungeon-Masters/151402/?play_immediately=1)
Or else is has now been released on DVD over here..