Mindflex, is a cool 2 years old gadget, which can translate a human's thought into control commands. 11 months ago, 3 people from mentalblock.net, Arturo Vidich, Eric Mika and Sofy Yuditskay managed to hack it and directly extract+visualize its data on the monitor of a PC, with the help of an Arduino board. Visit this link to read more about this interesting hack. They also wrote a library for Arduino for all those DIY fans, and also they offer the visualization software for free! Super!