spycatcher2k:
You can run it on 5V using the vin pin (as long as its a regulated input - e.g. Batteries or a wall wart) - it needs the extra voltage as it has a voltage regulator on the board that consumes 1.2V of the input voltage.
Incorrect. You can run it on 5vdc by using the shield's 5V pin using an external regulated +5vdc voltage source. The Vin pin only goes to the input of the on-board 5 volt regulator and must be minimum of +7vdc if used and then the on-board regulator will power the board.
Lefty