Gyroscopes. They help us
shake apps around on our iPhones (the iPhone doesn't have a gyroscope in it as reported — yet), simulate tennis and boxing on the Wii, and now they may even help you get that perfect swing. The Gyro Swing, by golf outfitter SKLZ (not to be confused with the 13-year-old from Ohio who uses the same name on XBOX Live), is equipped with a "20,000 RPM gyroscope ingrains the 'feel' of the perfect swing." If your stroke falls out of line, the club offers gentle resistant to intuitively guide you back to where the club should be.
Maybe you want one to train your arms. Or maybe you just want to get one up on your boss on the green. Either way the Gyro Swing won't judge, as long as you pay its $200 sticker price.
CORRECTION: The article above mistook the iPhone's gyroscope for its accelerometer. The section has been crossed out.