Today my boss wanted me to unlock his virgin iPhone so I did. My iphone was starting to be a bit flaky so I decided to upgrade mine as well. Mine being already unlocked 1.0.2, it was a little trickier but I followed the instructions here and voila (check out the nice T-Mobile logo):

Then I had to get my own ringtones on it using this. I now have the must-have CTU ringtone.