This is crazy: scientists in Japan have developed a way to read the visual information of what a person is seeing directly from their brains.
Subjects were showing simple 10x10 pixel images, like the ones on the left. The subject's visual corteces were monitored via a fMRI. The resulting images of activity were analyzed by computer, and the images on the bottom were reproduced.
Interestingly, this only took 12 seconds worth of input. That seems like a remarkably small amount to time, to me. Imagine what can be done with this sort of technology once it advances along.