No single writer has done more to change the way I think about science fiction than John Varley -- and now that his classic short stories (the very best of his work) are all available in one volume, you can have your head done in by a master without having to haunt the used book stores looking for out-of-print collections. Link (Thanks, Monty!)
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.