Stone Spray is a promising-looking 3D printer that is intended to produce building-scale structures by combining soil with binder from a spray-nozzle. Unfortunately, all the meaty tech information is locked up in a weird "book" player that doesn't work well on my screen, but you can get a general idea from the video above (I recommend scrolling at 10-20 second intervals and turning off sound).
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.