Nicholas Rougeux made this fabulous Menger sponge fractal out of mini Post-its, which he swears by for erecting fractals:
Each Post-It was torn into 16 equal squares, then folded into units and assembled into the sponge.
Post-its offer surprisingly structural durability and are easy to get in large quantities making them ideal for assembling structures like these.
Mini Post-It sponge [flickr.com]
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.