XonDemand is a VOD or Video on demand service that allows you to access and download movies on a per minute basis. They have a wide variety of material and sources. The movies and clips are sorted by type, star, and so on.
Currently (June 2007) they have a special of 15 minutes free for new members, which is a great way to try out video on demand.
* XonDemand - Check out the sample clips and take the tour at X on Demand.