The Arduino Esplora is the controller for DIYers who want to game with custom functions. The 6.5-inch preassembled board includes temperature and light sensors, an accelerometer, a joystick, and more, plus 32 kilobytes of memory. To begin programming, a user connects it to a computer via micro-USB. Arduino Esplora $65
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.