Interesting research being done using a webcam as a different type of input device – a controller for your desktop:
Getting physical « Canonical Design:
With the ingress in the market of products like Nintendo Wii, Apple iPhone and Microsoft Kinect, developers finally started realizing that there are several ways a person can control a computer besides keyboards, mice and touch screens. These days there are many alternatives, obviously based on hardware sensors, and the main difference is the dependency on software computation. In facts solutions based on computer-vision (like Microsoft Kinect) rely on state of the art software to analyze pictures captured by one or more cameras.