I love my treo 600 - have had it for about 6 weeks. No problems to report. I purchased it from a local dealer here in NYC. It came in an ATT box, but he told me it was unlocked and that it would not be a problem with TMO. Sure enough, it worked with my TMO SIM card without a hitch. Now that the firmware upgrade is on the horizon, I think that I should know what I have before I change it and screw it up. Here is what the phone info states:

Firmware : 02.09
Software: Treo600-0.0/921/02.0
Hardware : Treo 600.x.y

I am not sure if I will need to use the ATT or TMO upgrade and if it will undo the unlocked nature of the phone. Any help is appreciated. Thanks