Sir John B. Gurdon and Shinya Yamanaka just won the Nobel Prize in Medicine for their work changing mature cells into pluripotent cells--unspecialized cells that can become any other kind of cell in the body. This could be the the future of medicine. Imagine being able to regenerate damaged tissues by changing some of your skin cells into stem cells.
But let's not forget the little guys that make this possible. It's probably rather traumatic for them.