i saw this a while ago, it's a pretty cool concept, except it has some downfalls. you need to wear the marker caps on your fingers to give it a point of reference. with things out there like NATAL it seems outdated to have to have reference points. it also projects from your body, so you need to wear a rather bulky device. plus, it projects onto a wall so there is a security issue there, but then again just show restraint. ;Doh, they changed they changed it a little bit. in the demo video i saw a few months back the person needed to use marker caps on their fingers to use the device, looks like now you can have little colored rings before the 1st knuckle.