It's blue! It's skinny! It's the Arduino Pro! SparkFun's minimal design approach to Arduino. This is a 3.3V Arduino running the 8MHz bootloader (select 'LilyPad' within the Arduino software). The Arduino Pro is very much like the Skinny, but we added a handful of features to become a fully certified Arduino board. The power switch was moved to the side of the board (good idea Limor!) to allow control when a shield is attached. This board does not work with the 5V Arduino shields but does work nicely with our prototyping shield. 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 Diecimila. It's a great board that will get you up and running quickly. The Arduino Pro series is meant for users that understand the limitations of system voltage (3.3V), 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 Diecimila (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. Can't decide which Arduino is right for you? ! The Arduino Pro will slowly but surely be replacing the Skinny. Project description, more information and ordering can be found at https://www.sparkfun.com/products/8783 Arduino Pro Homepage: http://www.arduino.cc/en/Main/ArduinoBoardPro Getting Started: http://www.arduino.cc/en/Guide/ArduinoPro