The MYO armband uses the electrical activity in your muscles to wirelessly control your computer and your phone, not to mention your quadrotor UAV.
(MYO demonstration video)
The MYO senses gestures and movements in two ways: 1) muscle activity, and 2) motion sensing. When sensing the muscle movements of the user, the device can detect changes in hand gesture right down to each individual finger. When tracking the positioning in space of the arm and hand, the device can detect subtle movements in all directions.
Movements can be detected very quickly - Sometimes, it even looks like the gesture is recognized before your hand starts moving! This is because the muscles are activated slightly before your fingers actually start moving, and we are able to detect the gesture before that happens!
The MYO works out of the box with things you already have - like your Mac or Windows PC. You can control presentations, video, content, games, browse the web, create music, edit videos, and so much more. And developers are dreaming of new, exciting ways to use MYO every day. The MYO is a whole new way to interact with technology.
[MYO uses] a unique gesture that is unlikely to occur normally to enable and disable control using the MYO. The MYO alerts the user via haptic feedback to let them know when it is enabled and detecting movement.
Windows and Mac OS will be fully supported, and APIs will additionally be available for iOS and Android developers to integrate the myo on those platforms.
Ian Banks mentions something similar in his 2004 novel The Algebraist in this passage about a muscle sensor interface:
The ship accelerated smoothly but moderately hard, creating a distant humming roar. Fassin had a little pad under his right forearm which sensed muscle movements there and adjusted the screen across from him - above from him, now, it felt, as the couch straightened out and the gee-suit supported him...
Earlier, in Harry Harrison's 1960 novel Deathworld, here's another reference:
Here, take your left hand and grasp an imaginary gunbutt. Tense your trigger finger. Do you notice the pattern of the tendons in the wrist? Sensitive actuators touch the tendons in your right wrist. They ignore all patterns except the one that says hand ready to receive gun...
(Read more about Harry Harrison's power holster)