head-mounted displays you've had your follicles on, but generally the answer around the Engadget compound is, "quite a few." If you've ever played with such a wearable gadget though, you'd know that head-tracking, while intuitive, isn't always the most accurate way to control a device. Samsung has patented an alternative method that lets you keep wearing those silly goggles, but uses your cellphone almost like a gyroscopic mouse to pilot a pointer. Rather than use a gyroscope or accelerometer (both of which are present in many modern smartphones), Samsung's patent turns to the camera -- a feature found in even the lowliest dumbphone. The primarily software-based solution would require that both the phone's sensor and the display have an agreed upon background marker to help line up the motions. If you're the type that loves to dig through the minutiae of patents there's something seriously wrong with you, but you'll find what you're looking for at the source.