Here at RoboSavvy we are planing a Arduino + VEX + Linux Solution and to use the VEX motor controllers we need to power them directly from the battery and then control them from the Arduino.We needed to have a small PCB with pin headers and as we need something to hold the Arduino to the VEX chassis, we decided to create a holder that can handle both boards.We picked "the Printable Arduino UNO & Duemilanove Clip-in Holder by Darthwahl" (thing:9802) reduced the Arduino height, added the 4th pin to hold the Arduino, created the space for the small PCB, added the holes to match the VEX chassis and finally opened some space in the middle to save plastic.You can see more details of this project in our forum at http://robosavvy.com/forums/viewtopic.php?p=32042