A scientist hooked up some subjects to virtual-reality systems -- and hacked their brains into having an out-of-body experience. The experiments were based on a long-known trick called the "rubber hand illusion." In this one, people hide one hand in their laps while looking at a rubber hand on the table in front of them. A researcher strokes the fake with a stick -- while simultaneously stroking the real hand in precisely the same way. Pretty soon the subject begins to identify so strongly with the rubber hand that if you smash it with a hammer, the subject will freak out and "feel" the pain.