OmniTouch projection interface makes the world your touchscreen (video)
Sometimes you just want to make notes on your forearm. Put that permanent marker down though, because PhD student Chris Harrison et al at Microsoft Research have created a new system that allows touchscreen interaction on hairy and uneven surfaces. It uses a short-range depth camera instead of the infrared sensor we've seen on similar devices, which allows it to gauge the viewing angle and other characteristics of surfaces being used -- and it can even handle pinch-to-zoom. There's a video after the break, if you fancy a bit of wall-based digital finger painting.