There are lots of patents floating on gesturing. I think, like palm, the specific gesture can be patented, but not the idea of gesturing or the surface use, etc.
Apple is extending gesturing across their platform for the multitouch mouse pad and supposedly into the iPhone/iTouch (logical with those screens); http://www.macrumors.com/2007/11/22/...uring-patents/
With the iPhone/iTouch they have also patented movement of the unit using the accelerometer that is already built in - in fact the SDK already supports that and games will be out this summer that use the accelerometers (the things that allow their screens to flip just by turning the unit). They are also filing patents on use of the camera for motion detection/gesturing, etc as well.
I can just see all the bruised stomachs, sides and backs on the subway riders from over zealous game players flailing around on the crowded train.