Etsy seller Plastique's got laser-cut acrylic rings boasting pointy world monuments. As knuckledusters, they create the possibility of growling, "Right, mate, you're geography," before you bust your opponent in the chops.
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.