Multi-touch on laptops is a well-known feature of Apple portables, however it is a lot less known fact that MacBooks use practically the same touchpad hardware as other laptops and that other laptops are capable of multi-touch detection.
Most portables use touchpads made from Synaptics and newer versions of those do have ability of detecting multiple fingers, however the Synaptics drivers have this feature turned off for marketing reasons.
However it is possible to re-enable some of this functionality by using 3rd party software, the best by my experience being Two Finger Scroll project on Google Code. It enables you to use two-finger scrolling and two finger tapping, which is a rather puny set of features compared to Apple portables, however it still makes the use of laptop touchpad a lot easier.