MAKE pal and author William Gurstelle has an Arduino article in the Atlantic! The DIY Chip @ The Atlantic (January/February 2010)

HYSICAL COMPUTERS AS populist devices may be the most momentous tech trend of the past five years that practically no one has heard about. Typically a small circuit board housed in a customized case, a physical computer is an easily programmable device that is aware of its surroundings. It is designed to interface with sensors that measure things around it—say, how fast an object is going, how close something is to it, the temperature around it. Based on that input, the computer takes action by moving switches and levers, displaying information, or otherwise controlling the environment.

For humans, connecting to computers via a mouse and keyboard has long been cheap and easy. For sensors, not so much. Now an inexpensive physical computer called the Arduino is changing all that. When the Arduino burst onto the do-it-yourself (“DIY” to devotees) scene in 2005, all manner of tinkerers seized on it as a device that could easily and cheaply run interactive projects.

Using an Arduino is fairly straightforward: buy a board (ranging from about $19 to $65) and attach it to a personal computer via a cable. Then load instructions into the Arduino’s processor via the personal computer. Once programmed, the Arduino makes decisions based on the information transmitted by whatever sensors you’ve hooked up, and does something corporeal, such as turn on or off the motors, displays, valves, and lights attached to it. For a few dollars, creative and motivated individuals—rather than just corporations or institutions—can make highly intelligent tools, perfectly customized for a particular need.