Best suitable arduino board for breadboard prototyping. Small and powerful with ATMega328 AVR Microcontroller.
The Arduino Nano 3.0 is a surface mount breadboard compatible version of the ever-popular Arduino micro controller. It's small, has integrated USB, and is breadboard friendly. It has more or less the same functionality of the Arduino Duemilanove, but in a different package. Physically, it's missing the power jack, but it can still sense and switch to the higher potential source of power. It's perfect for embedding into your next project.
Arduino 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, MaxMSP). The open-source IDE can be downloaded for free (currently for Mac OS X, Windows, and Linux).