Got a folderful of movies of your kids? It'd be delightful to have them playing on your Mac as a full-motion family album. Or, suppose you're setting up a kiosk Mac where people are going to walk up, use it for a while, then wander away -- it would be nice if you could revert to an 'attract loop' of a QuickTime movie when the machine went idle for a few minutes.
Enter the handy (and free/open source) SaveHollywood screen saver module from developer Stéphane Sudre (also the force behind the indispensable Iceberg packaging utility). Select an individual movie to play back, or a folderful of clips -- you can choose to show the movies in fullscreen mode or at the original size of the source material, and you can adjust the sound to a custom level (or mute) if desired.
SaveHollywood is a 144K download and a Universal Binary. It's compatible with Mac OS X Tiger 10.4 and later.