I stumbled apon this thread while conducting research on wats been done so far.
if someone can post what sort of baseline wattage is required to move a person on 8 (or 4) comparatively small wheels then I can start prototyping based on a concept I've been working on (might post up my Pro Desktop pics some time soon but still a bit paranoid about posting unpatented concepts on the net.)
EDIT Never mind the last part!
p.s about the issue of each foot differing in speed you can sync them by a radio+speedcontroller if you get what I mean.