Movies can often be a great place to find cool sounds or weird little effects to add to your productions. The problem is, if you are watching the visual portion of the film while searching for sample fodder, what you hear may be prejudiced by the visual that goes with it. Sometimes, ignorance is bliss when it comes to this sort of thing, and with the visual element removed, you rely only on your ears and may begin to perceive things differently. Most notably, you'll probably notice small, incidental sounds that you might not have otherwise, and these hidden treasures can sometimes become the basis for cool percussion sounds, or even odd rhythmic loops.
So the next time you want some new sounds to feed your sampler, load a DVD into your computer and use a utility such as the excellent Audio Hijack to just record the audio portion of the film. Later, load up that file in your favorite audio editor and begin listening for bits to snatch. You'll be amazed at the cool sounds you were missing before!