If you look at all the surface computing systems that Microsoft is working on it is easy to see what the folks there think the future of computing will be. Microsoft thinks the future will be touch interfaces and the ability to interact with virtual constructs with your own hands. The latest cool example of the future tech that Microsoft Research is working in has surfaced and it is called Holodesk.
The research project came from the Sensors and Devices group from Microsoft Research Cambridge. The idea behind the Holodesk is that you can build and then interact with 3D objects with your bare hands. I can see some use for this tech in different areas ranging from gaming to engineering where something can be made with CAD and then manipulated on the desk.
To be able to view the 3D objects, the user does need to be looking through the plastic or glass sheet you can see in the video. If you look at the display screen underneath without peering though that plastic sheet you see nothing. I hope they can scale it up and make me a Star Trek Holodeck.