A recent video demonstration by Microsoft shows off their new technology that allows almost any surface to be used as a multi-touch screen.
The OmniTouch device featured in the video uses a combination of a laser projector and a depth sensing camera to identify the users hands and detect when the surface has been touched without the use of sensors.
The display can be projected onto almost anything including common surfaces such as walls, desks, notepads and even the users hand or arm!
After deciding which surface to use from a massive selection that the device offers, the user can interact with applications without any training or tedious device calibration.
You can watch the video demonstration here :)