Apple has applied for patents on a series of single and multiple touch gestures that will undoubtedly show up in some iteration on their Mac OS X sometime in the future. Of course Apple already uses a limited number of touch commands on some of their hardware, but the series of gestures outlined in the application indicate an enormous amount of possible gesture commands.
They also claim to be able to distinguish between various combinations of fingers, including adjacent and non-adjacent finger presses. In particular, they point out that the pinky finger when applied sideways to the trackpad (as in the bottom of a fist) generates a unique pattern and could be used for its own customizable functionality: such as adjusting volume or putting the computer to sleep.
I hope if you sneeze while using the touch commands you don't wipe your hard drive clean.