In tomorrow's edition of Nature a team of researchers will publish results of a clinical trial of the BrainGate Neural Interface System, a "neuromotor prosthesis" developed by Cyberkinetics Neurotechnology Systems.

The first patient, Mr. Matthew Nagle, a 25-year-old man with a severe spinal cord injury, has been paralyzed from the neck down since 2001. After having the BrainGate sensor implanted on the surface of his brain in June 2004, he learned to control a computer cursor simply by thinking about moving it. During 57 sessions Nagle learned to open simulated e-mail, draw circular shapes using a paint program on the computer and play a simple video game, "neural Pong," using only his thoughts.

The Cyberkinetics BrainGate System consists of a 4x4 millimeter sensor with 100 tiny electrodes, each thinner than a human hair.

This is amazing news to actually have a brain-implant already working on humans. What we know from science fiction has become a reality.
More details in this press-release. I guess the best way to get all the details is to go out tomorrow and get a copy of Nature. See also the Cyberkinetics site.