Hardware-free motion motion controls!
OpenHand is an open-source library that uses OpenCV to recognize the position of a user's hand. It does this by detecting colors on the fingers of a glove that anyone can make with some markers, tape, and any black glove. It is aimed at game developers who want to integrate simple motion controls without requiring the end user to purchase expensive hardware. As stated, the glove can be made by the end user fairly easily, but could also be mass produced at an incredibly low price (the price of making any regular glove).