Nintendo Wii Balance Board gets you stepping in upcoming Wii Fit title
Following on from Heather’s comment about the Wii balance board, I have been thinking about additional sensors that could be added, but my thoughts were more along the line of ankle sox with motion sensors so footwork could be added, probably a belt for waist movements and maybe elbow sox for better arm manipulation detection. ( when playing tennis, my son defeats me by doing little flick shots that would not work in real tennis). There has been lots of work in this area though as a simple search will show, see
Nokia has built and tested a fitness game for children using mobile phones but it appears to be poorly reported. Involves group tasks using location detection and group pressure to get “lazy” members to complete the tasks and score group as well as individual points.
(I will add a link)
A local mobile Phone based company Socoto Studios have built a running/jogging game with similar themes, that helps you join up with other runners ( I believe!).