Here is an utility to easily switch to Roaming without having to go through all the phone settings or registry hacks.
Original link for Touch Pro:
http://forum.ppcgeeks.com/showthread.php?t=104097 <-- PLEASE THANK THE ORIGINAL AUTHOR!!
The above did not work correctly with the Touch Pro 2, so I modified it with the author's permission to make it work with our phones, and created a cab for easy installation / uninstall. Hope it helps!
