CES isn't just about 4K and connected cars; it's a place where you can get a look at prototype technology from some of the biggest companies in the world. In Sony's booth this year, it's showing off what it calls the "Tennis Sensor." The small nub affixes to the end of an ordinary tennis racket, and is able to detect the motion and vibration of the racket whenever you hit a ball. That information is then sent via Bluetooth to a tablet or smartphone, where Sony's software can tell you the speed of your swing, the type of swing, and even where on the racket you connect with the ball.
Unfortunately it's still in the prototype stage at this point, but a shipping product based on the technology could be a great fit for people trying to improve their game. The best part? You don't need to know anything about tennis to give it a try. Believe me.