Hitachi have developed a brain-reading device which uses near-IR light to watch blood-flow in the brain - a proven proxy for simple, strong thoughts.

Hitachi's Brain-Scanning Remote

In essence you'd wear a near-IR pick-up as a head-band and it would allow you to think simple commands on a remote control. They're hoping to market to disabled people, but I can see the idea spreading and being refined to give us 'thought recorders' and the like. The US DARPA worked on sub-vocal communicators for a while which sensed the impulses to the vocal-cords which occur when we're "talking in our heads" - I'm not sure how well that project went, but it would also allow for 'thought recording' or at least a sub-vocal Dictaphone.

Will we have it first appearing as a hobbyist craze - 'stick to your head Thought-Buttons' - advertised with telescopes and computer projects?