this might help a bit
http://www.eastcomultimedia.com/customer/order/copyright?copyright=sample
i dunno if that'll help much. but essentially, if you wanna be rich and famous using someone else's recorded material "in whole or in part" (as it says at the beginning of every movie), be prepared to pay through the nose. that is, if it's some big money movie like the Matrix or Titanic or something.
i think there is a good chance though, that some smaller, virtually unknown movies might be happy to let you use some samples for a significantly smaller fee. in the end, you might end up helping them out, because if someone loves your track which uses the sample from said movie, your fan might be driven to rent this movie as well. kind of a "symbiotic relationship", if you will.
however, some more well known artists even, as far as i know, seem to have slipped through the cracks and gotten away with sampling. i highly doubt Tricky has ended up paying royalties on every sample he has ever used. if so, he'd be probably more poverty stricken than me.
it's just a matter of getting caught.
and God, i hope i don't get caught.
i can't afford it