I work on a magazine for the British Association of Prosthetists and Orthotists so get to see pictures of some of the fantastic prosthetics out there (and unfortunately of wounds that would put you off your dinner). Enough titanium and carbon fibre to make the weight weenies weep, and silicon hands and feet with hairy toes/fingers and everything. It's really is amazing what can be done. The engineering involved in knees for instance, is particularly impressive.
There was an article about a year back about one guy with no arms, (and I think, only one leg) who cycled across America. I must try and dig it out.