Sporting a device reminiscent of the shoulder weapon from Predator, a man slowly appoaches a white-washed wall. Suddenly, at the touch of a finger, images and words spread out around his hand, giving him direct access to the previously unseen digital universe. His gestures and manipulations change that world. Then, satisifed, he closes his view of the digital world and walks away.
The technology is a demonstration system from Microsoft Research that can use any available surface to act as the interface for user interaction. See a video and links here: http://research.microsoft.com/apps/video/?id=160684
As the technology shrinks and new ways of using the technology advance, expect to see the requirements for a surface dissappear, with the depth sensor working directly on images augmented to the users reality. Sci-fi tech seeping into the real.