There are some cool uses for Nokia’s Mobile Radar which can be incorporated in a mobile device, which they demoed recently. They showed an actual working radar on a modified version a N95 handset.
In the video shown below, you’ll see researcher Jani Ollikainen use his hand to adjust the music player’s volume, without ever touching the hardware. Even with an object in his way (like your pants pocket or even a wood door), the radar works without a hitch. In the second demo, you’ll see fellow researchers Terhi Rautiainen and Risto Kaunisto measure the distance, speed, and direction of a human walking.