Does anyone know anything about or knows resources to find out the legality of using sampled sounds (specifically spoken words) from movies and using them in an iPhone app?
Do NOT do it.
Since day one we have used 100% royalty free, purchased or original sound clips. We consistently get requests to add sounds from movies, TV, etc., even though our web site says we will NOT use copyright protected sounds. We always say no.
Our sounds are all legally licensed. I've had to provide documented evidence of this to Apple in fact, so I'm glad I stayed on the right side of the law. I don't want to get into any NDA-related details, but trust me, don't do it.