Peter Lutjen came up with a bunch of different designs that eventually evolved into the final. The penultimate version used a photo-realistic illustration that everyone almost loved. One last tweak of the design was to have the imagery re-drawn in a freer more organic style by Yuko Shimizu -- that seemed to unify everything to everyone’s liking.Link
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.