Microsoft has been demonstrating some interesting technology at its annual employees-only TechFest event. Microsoft's Surface technology is great, but it's also large, expensive and a little unwieldy. Allow Mobile Surface to step into the ring instead.

It projects a screen onto a surface, but then is able to sense where your hands are and allow you to manipulate that screen. It's sensitive enough to allow you to detect how high your hands are - the Microsoft employee demonstrating the tech showed control of volume by moving his hand up and down above the screen.

Microsoft hasn't said when any applications will be available, but a similar product was shown off at CES by a UK company - Light Touch. Its projector enabled a 10-inch image to be interacted with when beamed onto a surface, using infrared to detect hand positions.