While making a large batch of chicken stock this weekend, I was flipping through the boob tube and came across one of those infomercials hawking a new pressure cooker set.  They talked about how quickly you could make stock in a pressure cooker.  That made me remember that guy on the Food Network, Alton Brown, doing a similar show on stocks cooked in a pressure cooker. Has anyone tried this, and does it actually make a quality stock in less than half the time?