3D printers are great for making things, including more of themselves. The first really accessible 3D printer, the RepRap was designed to be buildable from locally sourceable components - metal rods, bolds, screws, and wires, and the rest can be run off on another 3D printer. There is even a variant called the JunkStrap which, as the name implies, involves repurposing electromechanical junk for basic components. There are other useful shop tools which don't necessarily have open source equivalents, though, like laser cutters for precisely cutting, carving, and etching solid materials. Lasers are finicky beasts - they require lots of power, they …

It’s only in the past quarter-century or so that semiautonomous sensor platforms – self-powered robots equipped with cameras, rangefinders, and the like – have really advanced to the point where they’re feasible for field work. Right off the bat, everyone thinks of the UAVs deployed in Iran, Iraq, and elsewhere or sophisticated robotics projects developed by hackers, but why stop there? When you consider practical sensor platforms most of them aren’t subtle: they’re the size of a model airplane or larger, and depending upon the method of propulsion used you might even hear them before you see …