Originally Posted by Boy Genius
Are you kidding me? If its unlocked it will work on any carrier that has a blackbery plan...
I don't think you are totally correct, Boy Genius. If you have an unlocked GSM phone it will work, in theory, with any GSM carrier, such as Cingular or T-Mobile. It will not work on CDMA carriers such as Verizon and Sprint/Nextel. I don't think any US phone will work in Japan or China. I think GSM will work in Europe.
I say in theory because it is really up to the carrier to allow the device on their network. I have heard that Sprint will only allow their own branded phones to operate on their network. I do not think Cingular and T-Mo are of that same opionion, however.