I found the article about robot called Manoi. This is going to be retailed. It costs over US$1,500, but you can register motion and program actions. It has may motors, gyros and sensors to balance its body.

http://www.youtube.com/watch?v=f5T0to-PVfY&feature=related

As usual, I imagine that I program to let it play DDR with dance mat... We need to make a small and sensitive dance mat. It may be possible to program play certain song with preset action sequence, but it must be hard to program to let it think, judge and play any song on the fly. DDR is a very simple game, consisting of just 4 directions, but it requires so various body moves. Human is intelligent enough to control body naturally, but it is logically difficult.

When you play DDR, you use your left foot to step on LEFT, right foot on RIGHT I guess. How about UP(forward) and DOWN(rear)? The best way is to use a free foot. For example, if arrows come L-L-U, you can use your right foot for UP because your right foot is free. If it is U-L-L, again use your right foot for UP because you will use left foot for following LEFT. If it is U-L-R-U, use right foot for the first UP and  left foot for the second UP. Foot to step UP and DOWN depends on the next or previous steps. Sometimes such logic does not work, but then you need to devise. Also some beginners think that they need to put your foot back to the center position after step, but you don't have to. The game checks the moment you touch(press) the button, so you can keep your foot on the button after that. Good DDR players instantly know how to move their foot balancing their bodies, but it should be hard to program the robot to do that on the fly. I would not say it is impossible because the moves are not unlimited even though it is complex and there are various combinations of moves, but it will cost.

Hiro@LA