The people at the Nokia Research Center in Finland saw what accelerometers in iPhones allowed apps to do and have taken things a step further. Nokia researchers compressed the radar technology used in police radar guns and made it small enough to fit in a cell phone.
This "mobile radar" could potentially revolutionize the way people control their cell phones as the radar can determine the distance, direction and speed of an object in relation to the phone.
In the video below, researcher Jani Ollikainen shows how he can move his hand away and toward the phone to control the volume of music playing. Even when he covers the phone with a hat, it still registers and responds to his movement. In theory, this will allow you to control your phone without ever touching it, even if it's in your pocket or in a purse.