Researchers at Carnegie Mellon University are working on a device that projects an interface onto a user's body, which can then be used to work mobile devices:
It's called Skinput, and here's how it works: The use wears an armband, which contains a very small projector that projects a menu or keypad onto a person's hand or forearm. The armband also contains an acoustic sensor. Why? Because when you tap different parts of your body, it makes unique sounds based on the area's bone density, soft tissue, joints and other factors.
The software in Skinput is able to analyze the sound frequencies picked up by the acoustic sensor and then determine which button the user has just tapped.
Link via Popular Science | Official Website | Photos: Chris Harrison