Sorry, can't help with code. If you find a shield I would expect the maker to have examples. Also you could have a look on the Arduino playground,
http://playground.arduino.cc//Main/HomePage
there might be some code there.
EDIT: Have a look at this thread
http://forum.arduino.cc/index.php?topic=173216.0;topicseen
EDIT1: Oh, I see you found it
Rob