Clone Ver.

Arduino Nano is a surface mount breadboard embedded version

with integrated USB. It is a small, complete, and breadboard friendly. 

 It has everything that Diecimila/Duemilanove has (electrically) 

with more analog input pins and onboard +5V AREF jumper. 

Physically, it is missing the power jack. 

The Nano will automatically sense and switch to the higher voltage 

source of power, there is no need for the power select jumper.

Nano's got the breadboard-ability of the Boarduino and the

Mini+USB with smaller footprint than either, so users have more

 breadboard space. It's got a pin layout that works well with the 

Mini or the Basic Stamp (TX, RX, ATN, GND on one top, power and 

ground on the other).