That leap may be at hand. Small electroencephalograph (EEG) sensors that track and interpret brain activity can be built into a headset or cap and may prove be a good stand-in for interpreting fMRI readings.

Primarily used in medical research, such devices are also appearing in everything from "neuromarketing" aids (wireless headsets that register test subjects' responses to marketing and branding) to crude toys that, for instance, let you pretend you're a Jedi knight by controlling a ball's height with mental power. Recently, a group of German engineers operated a specially modified car with one.

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On the computer interface front, Austria-based G.tec showed its Intendix system at this year's CeBit show in Germany. It uses an EEG cap studded with electrodes in conjunction with software you load on a Windows PC. The interface is laid out like a typical qwerty keyboard, with a few additional symbols for things like printing and sending email. After training the system, all you do is stare at the Intendix screen and think about the letters, numbers or symbols to spell out your message.

At the moment, the system can recognize about five characters a minute -- not exactly speed typing, but it's a start. Because of the system's $12,000 price tag, brain-powered computing will probably first be used for people with limited voluntary muscular control or "locked-in syndrome" diseases including amyotrophic lateral sclerosis (ALS), a.k.a. Lou Gehrig's disease.