First off, the "secret sauce" of the solution is called a "DigiTarget". The DigiTarget gives everything in your photo a frame of reference; it's a single sheet of paper with a 7.5 x 7.5-inch square on it. A 15-inch square version is also available for outdoor measurements. Simply print off a free DigiTarget, affix it to something in your photo scene and snap a pic. The iPhotoMEASURE software uses the DigiTarget to compute the measurements of items in your photo and the company claims that any distance in the picture can be measured with up to 99.5% accuracy. Conceptually, it makes sense since the software has that 7.5- or 15-inch frame of reference.Link (via /.)
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.