In this sixth sense technology, Pranav Mistry talks about imagining about things that we do in a digital system. We can then replicate the same in our human world without the use of computer systems. We can do that using rollers and a camera to understand our needs. Rollers are used by the camera to understand our hand gestures.
It is simply brilliant of this guy to have come up with high number of unheard stuff and turning them a reality. Some really cool innovations he has come up with are the SixthSense, Teletouch, Mouseless etc.
There are a host of other innovations that you can read about and possibly try it on your own. You can read all about it in here.
Enjoy the change :)