Apple has won a US patent on an unusual tablet-based graphical interface. The UI would not only make use of touch and motion, as iOS does currently, but simulated physics -- including mass, gravity, friction, and/or drag. A basic example involves selecting multiple files or folders; by drawing a circle around them, users would create a selection "bubble" that could be behave like a floating ball, even bouncing off of screen edges. File and folder size could dictate mass, such that a larger file might move more slowly.
Pushing
the concept even further, a user could conceivably "pour" files from one device to another using the appropriate gesture, assuming the devices already have a wireless connection. Pinching selected items could compress and archive them, and shaking a device could sort files, snapping them to a grid in rows governed by filesize, with rows containing larger files skewing towards the bottom.
An application for the patent was first submitted in February 2010. It's unclear if Apple will ever implement the idea, since as it stands iOS lacks an open filesystem, and OS X has limited touch and motion functions.