I've been tracking this project for a while. The most interesting part is that much of the work is done by undergrads. That's really impressive considering how hard robots are to make.
Nice! Those videos are awesome. CMU RI = made of win.
Another interesting project they've got going (which seems like it might be related) is their work on modular robots using electromagnetics or static charges. http://www.youtube.com/watch?v=e44hA6IBtkA (Link goes to a short New Scientist clip regarding the project.)
Don't miss the salamander robot. Last Summer in Telluride's neuromorphic engineering workshop the lead researcher gave us a very impressive presentation on it. It's all about coupled oscillators: for each lateral side of each spinal cord segment, and also some overriding ones for the limbs that fire off at certain activity level of the spinal cord ones.
AJ Ijspeert, A Crespi, D Ryczko, JM Cabelguen. "From Swimming to Walking with a Salamander Robot Driven by a Spinal Cord Model." Science 9 March 2007: Vol. 315. no. 5817, pp. 1416 - 1420
