From All Too Flat Software:
Particles is a screen saver of particles combining and exploding as they bounce around the screen. The parameters of the physics model are highly customizable, and include the following interactions: gravity between particles, fusion of colliding particles, elastic collisions between particles, and much more. Supports multiple monitors.
This review was originally posted on VersionTracker.com. As a screensaver itself it's cool, but not tremendously special. However, it's the first screensaver I've found that treats my three monitors as one, and for that I give you serious kudos. Well done!