A robotics researcher I know through Twitter forwarded this link to me and asked if anyone on LMR had worked with electromyography (EMG) for controlling robots. This looks pretty interesting and seems approachable for a hobby robotics budget and complexity.
The website shows videos of EMG control over motors and servos.
Curtis Boirum, a grad student at Bradley University, in Peoria, came up with this unique drive system using a motor spinning a hemispherical pad on a two-axis gymbol. Check it out. It is pretty amazing and may be something worth experimenting with.