While I doubt that physical controls such as keyboards and mice will ever go away, motion controls are growing more common and popular. The many motion control systems currently available use a variety of technologies, but most if not all rely on being able to see the user. That is not the case with WiTrack, a new system developed by MIT researchers as it can capture your motion through walls.
This is not MIT's first venture into motion tracking through walls, but the previous attempt, called Wi-Vi, relies on Wi-Fi signals. The new WiTrack system instead uses lower energy signals that allow for much higher accuracy. Specifically, it is able to determine a person's position to within ten to twenty centimeters. The hardware achieving this includes one transmitter and three receivers, while the software uses algorithms capable of filtering out echoes and identifying when the pulse of radio waves was emitted. Combined this is able to not only follow you behind a wall but also track gestures, so you can turn lights off in another room, just by pointing in the right direction.
It is easy to see the WiTrack technology being used for video games as well as monitoring elderly people at risk of falls, but its true potential may be far greater. This is in part because the radio signals it uses are of very low power (100 times less than Wi-Fi and 1000 times less than what cell phones use) and the physical technology is already cheap to produce, and could be made cheaper.