It looks like just a concept right now, but if it becomes a reality, that would be awesome for board games on the iPhone. (i)Pawn seems to use different voltage cell-sized batteies to distinguish different playing pieces on the iPhone (I’m guessing iPad too.)
Volumique is working on the app, and has some videos of it in motion here.
The uses of such a technique are limitless in the world of games. It may even bring back the dreams we had when we heard about the no defunct Philips Entertaible.