Theres a lot of mention of being unable to modify the DNA of adult organisms, but there are a series of experiments using viruses to modify the DNA of adult animals. ranging from giving colour sight to colour blind monkeys,

http://www.timesonline.co.uk/tol/news/science/medicine/article6837392.ece

and making remote controllable mice by making their brains seceptable to certain colours of light.

http://singularityhub.com/2010/03/18/incredible-video-of-using-light-to-control-the-brain-of-mice/

I'm not sure how to edit a trope, So thought I'd give the information source so someone else can do it.

Shouldn't Spongebob be mentioned in this? He can rearrange his body parts so I guess it should count

Does anyone have a firm idea on how to write this trope's Playing With page? I would've done it myself, if I had the slightest idea on how to play with this trope in the first place.