The University of Calgary and MDA, the company that manufactured all the Canadian robotics on the space station, have teamed up with the faculty of medicine there and created something called neuroArm. NeuroArm is a neurosurgical robotic tool--not experimental, but operational--that uses the control algorithms and the vision system from the Canadarm to perform surgery on human brains. The reason they do that is that a robot can hold a precise tool at a precise location in the brain a lot better than even the steadiest neurosurgeon's hand, so I think medicine has probably benefited the most from our space investment.
On May 11th, 2010. See this statement in context.