pi the movie (made by darren arronovsky who later made requiem for a dream) was a good independent film. and it was made on such a shoestring budget: money was thrown in by friends, who in turn were promised a share of any profits. i think they had to do it for under $50,000. the dvd i got was good, because it explained the process of getting it made (raising funds and stuff), and darren did a commentary, in which he explained how the different scenes were shot given the monetary constraints, eg. he used family and friends in roles.