I've been using Nike+ Kinect for 5~6 weeks now. It creates a workout plan for you based on an assessment that you do at the beginning. I've found it to be very

I've been using Nike+ Kinect for 5~6 weeks now. It creates a workout plan for you based on an assessment that you do at the beginning. I've found it to be very challenging at times (when I push myself, e.g. by doing a second round) and now I'm additionally impressed: a lot of the lower body stabilization exercises on this PDF are also exercises that the game assigned to my workout plan.