SKLZ Gyro Swing Trainer

You can't hit balls with this whirring wonder, but the Gyro Swing trainer (a Fore Inventors Only semifinalist) can help hone your sense of the swing plane. The goal is to swing the club without resistance–a gyroscope in the head provides an uncanny correction when the club gets out of position. A black-and-yellow shaft provides helpful visual feedback as well: during the swing, only the black portion should be visible. Beginners, especially, seem to love what the Gyro Swing tells them. Includes a DVD of practice drills from top instructor Rick Smith.