LeafPDX's PrimoGraf is a $150, laser-cut hyper-Spirograph-like device that makes extremely lovely, intense geometric doodles in infinite variety.
The PrimoGraf is a hand cranked drawing machine. Using wooden gears with prime number based gears an infinite array of drawings can be made. It comes complete with 7 gears, 2 set of rods and penholders so you can create many variations. Different setups can be achieved instantly by simply picking different holes. Made of walnut, basswood, and solid brass and hand crafted in Portland, Oregon.PrimoGraf Drawing Machine (Thanks, DugNorth!)
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.