Originally Posted by miamibusta69
the new iphone is ona differnt channel and will not work no matter what it is the chip set it has nothing to do with being unlocked.
why do you think the old iphone costs more than a new one?
just buy the old one or go to att simple as that
iphone is a quad band phone (850,900,1800,1900), it can be used anywhere in the world once it's unlocked.
to the OP,
the differences between 2g and 3g iphones are 3g and gps, since you will be using it on tmobile, you might as well get the 2g since you wont be able to use 3g network on tmobile and gps needs internet to access google map.