Thanks to our smartphones and tablets, gyroscopes have become more and more commonplace. So why not put them to use for more than just rotating our photos and playing games? The Black & Decker Gyro Screwdriver ($30) does. Thanks to an internal gyroscope, it automatically senses whether you want to go in forward or reverse, and at what speed, all based on how much you turn your wrist. It can operate at up to 180 rpm and apply up to 35 inches per pound of torque, making it plenty powerful enough for most jobs, and it sports a built-in LED lamp to let you see what you're screwing — which is almost always a good thing.