The very cool folks at NXTLOG put up a rather ambitious contest this month.
they want us to build biped
s
Nxtlog Biped challengeI've tackled this idea before twice and its pretty complex.  At least the way I tried. 6 motors,  2 Nxt Bricks..12 batteries and I even cracked a motor (had it sent back and all that ...go Customer service!).  But there have been those who have put up some great robots, single motor up to only 3 motor bipeds.  Lets see what the community can do with this one!