Blood Lamp (via Cribcandy)
For the lamp to work one breaks the top off, dissolves the tablet, and uses their own blood to power a simple light. By creating a lamp that can only be used once, the user must consider when light is needed the most, forcing them to rethink how wasteful they are with energy, and how precious it is.
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.