"Well, brain to brain, obviously." He described something he calls a "brain cap," by which people could swap thoughts in the air. Instead of blowing a kiss to your spouse at the airport, you could blow him or her an entire farewell letter, with photos and audio clips. Brain caps, he explained, would also eliminate menial tasks. "I think it's imminent," he said, "for some simple things like switching lights on, or the air conditioner, or starting your car."