ArtFall, a collaboration between Brent Bushnell and Eric Gradman @ Mindshare Labs, creates a 2D physics simulation from hand drawn art. Eric explains –

Basically, you draw on a whiteboard; a camera captures what you’ve drawn and inserts your art into a physics simulator. Objects are then “dropped” from the top of the whiteboard and bounce off your artwork. The simulation is projected as an overlay back onto the whiteboard.

Some interesting variations are demonstrated in the above video – of course many more possibilities remain. Hmmm … different colored markers for multiplayer whiteboard gaming? Read on for more info – ArtFall