Even with very invasive techniques (chronic implants), the reading of motion signals for example is very problematic. One of the first devices to do that is the

Even with very invasive techniques (chronic implants), the reading of motion signals for example is very problematic. One of the first devices to do that is the http://en.wikipedia.org/wiki/BrainGate http://en.wikipedia.org/wiki/BrainGate . It requires substantial training and retraining because of brain plasticity. Still, these are major breakthroughs, and hopefully we will be able to find a reliable and usable signal, but i agree, EEG is too bulky for that purpose.