Our hack is basically a robot which moves forward with it's speed depending on the user's concentration. The more you concentrate, the faster it moves. If your concentration decreases, so does the speed.
We've used a special gel-less EEG(electroencephalogram) device and have basically deciphered a few waves( http://tinyurl.com/3gne6u9 ) of your brain. This is just a proof of concept and further implementation to control wheelchair etc is possible.