The HowardForums thread on the 6263 have been informative. There are reports that, as a general policy, T-Mobile is disabling the feature that permits apps (j2me ones) to access the network, so things like Google Maps can't work. I've noticed this on my current dying phone, but I figured it was Samsung being annoying, not T-Mobile, since I couldn't find that the option existed at all. The "free" alternative seems to be the 6267, which as a bonus also has a 2MP camera insetad of 1.3MP.