­Check out this research from Microsoft (actually posted by TechFlash.com. They show devices and Guitar hero being operated by Electromyography (the same technology used to operate artificial limbs).

Clever applications – I think if they can make the “wearing” of such a device easy and inexpensive, we could eventually see this used in consumer products. The easy part is the idea, which now seems so obvious. The hard part is commercialization.