Researchers in the laboratory of Boston College Chemistry Professor John T. Fourkas have demonstrated the fabrication of microscopic polymeric structures on top of a human hair, without harming it...Link (Thanks, JeremyT!)
One could imagine, for instance, building devices directly on skin, blood vessels, and eventually even a living cell. While this idea is currently in the realm of science fiction, our results represent an important step in that direction.
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.