ThinkGeek's $25 Blazing Skull Bicycle Tail Light has a pair of "laser cannon" that draw six-foot lines of red light on either side of your bike, creating "your own glowing bike lane."
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.