Arduino Nano Development Board

Arduino Nano Board is an open-source physical computing platform based on a simple I/O board and a development environment that implements the Processing/Wiring language. Arduino can be used to develop stand-alone interactive objects or can be connected to software on your computer (e.g. Flash, Processing, and MaxMSP). The open-source IDE can be downloaded for free (currently for Mac OS X, Windows, and Linux). It lacks only a DC power jack and works with a Mini-B USB cable instead of a standard one.