Magic Trackpad

The Magic Trackpad  (model number A1339) is the trackpad by apple that makes use of Apple's Multi-Touch  technology.

Scroll - two fingers
two finger swipe - go back
Switching Apps with four fingers across
control button- two fingers zoom in or out
Four fingers down - expose mode
Four fingers up - clear desktop

This video goes over features by Soldier Knows Best:

https://www.youtube.com/watch?v=GF5IPPrx17A