Wired News: It's Alive (ish): "When Rene Descartes said, 'I think, therefore I am,' the philosopher probably didn't imagine a stamp-sized clump of rat neurons grown in a dish, hooked to a computer.
For years, scientists have learned about brain development by watching the firing patterns of lab-raised brain cells. Until recently, though, the brains-in-a-dish couldn't receive information. Unlike actual gray matter, they could only send signals.

Scientists at the Georgia Institute of Technology figured they could learn more from neuron clumps that acted more like real brains, so they've developed 'neurally controlled animats' -- a few thousand rat neurons grown atop a grid of electrodes and connected to a robot body or computer-simulated virtual environment."