I caught part of Nova recently when they were discussing building human organs from your own cells. Some folks started with a scaffold from an existing organ and added new cells, and these other guys PRINTED a mouse heart with an Injet printer.

Watch the video if you can, or you can read the transcript. It's amazing! I want this to be perfected so I can replace my ... well, whatever decides to fail first! Even better than replacing your bum heart, print me one with upgrades!