
I'll post more on this later (post prelim), but
Wired has a nice overview of the DARPA arm project. They make mention of the Deam Kamen arm as well, and that the current control mechanism for both is myoelectric (EMG pads recording rerouted, off site, or residual muscle movement).
I just thought I'd mention that the reasons many of my posts are relate to robotic prostheses are that:
1) They make for good media, so they get plenty of coverage
2) They represent something of a parallel but separate line from what I do (decoding = neuroscience, prosthesis = engineering)
3) Aside from implantable stimulation systems, artificial prosthetics are the Mecca of neuroprosthesis. Cursor movement is great, but it doesn't tie your shoe. Additionally, they provide the possibility of extending the human body. In Sci-Fi Fantasy Future Land, there is always the possibility of having more than two arms (you laugh, but there's no evidence that this would not be possible!)