Stem cells could be great. Well actually they are great, when you start life(ish) as a bundle of cells, they're the cells you consist of. Cells that can grow into anything are of course very usefull. Need a new leg? Grow/clone some new stem cells from yourself and use them to grow a new, genetically identical, leg.
The problem, as it always is, is making that actually happen. You don't need to figure out the practical use of stem cells, we know what we want to use them for, we just can't do it. Hence the research.
But still, glowing pigs! Do you need a reason to meddle with nature when the results are this good?
