Those muscle spasms? They're now good for something. Okay, so Microsoft's just-granted patent for a wearable EMG device doesn't really thrive off of involuntary twitching and such, but it does use your movements to control your smartphone, notebook and other gadgets. The "Wearable Electromyography-Based Controller," which we first glimpsed back in 2010, uses sensors to interpret the electrical signals generated by a user's muscles, and then communicates with the wearer's computer via a wireless (or wired) connection. Redmond envisions the wearable device in various incarnations: as an armband equipped with sensors, a shirt, eyeglasses and even nodes attached directly to the user's body. In the armband example, motion control could be used to interact with a PMP while the user is jogging. No matter the setup, a calibration process allows the system to locate specific sensors and collect information based on specific gestures or movements, which means playing Guitar Hero with only an air guitar may someday be a reality after all.