picoduino
http://bytebucket.org/ricklon/arduino-wine-in-box-bot/wiki/Home
ardweeny
Yes, You need to buy/make a voltage regulator like this the breadboard voltage regulator as there is no voltage regulator on board.
smallest arduino board
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1239733868/all