It's blue! It's skinny! It's the Arduino Pro! SparkFun's minimal design approach to Arduino. This is a 5V Arduino running the 16MHz bootloader (select 'Arduino Duemilanove w/ 328' within the Arduino software). The power switch was moved to the side of the board (good idea Limor!) to allow control when a shield is attached.
Please note: The right-angle power switch is fragile. We're working on making the switch stronger. For now, please be gentle.
Arduino Pro does not come with connectors populated so that you can solder in any connector or wire with any orientation you need. We recommend first time Arduino users start with the Duemilanove. It's a great board that will get you up and running quickly. The Arduino Pro series is meant for advanced users that understand the limitations of system voltage (5V), lack of connectors, and USB off board.
We wanted Arduino Pro to be low profile. The DC power jack footprint is available, but not populated. We recommend running the board with a LiPo battery for better portability.
We really wanted to minimize the cost of an Arduino. The Arduino Pro is like the Arduino Duemilanove (same pin out) but to keep the cost low, we used all SMD components, made it two layer, etc. This board connects directly to the FTDI Basic Breakout board and supports auto-reset. The Arduino Pro also works with the FTDI cable but the FTDI cable does not bring out the DTR pin so the auto-reset feature will not work.