This is just so sad. T-Mobile’s branded phones now block any third party Java app from accessing their network! You might have to buy a more expensive data plan to unlock your phone’s third party capability, or another phone+plan. This is just terrible. The world is going towards mobile devices and T-Mobile is trying to shrink their usability. How shortsighted. Now apps like Opera Mini and Google Maps/Gmail don’t work anymore!
One more reason to buy unlocked phones. Never agree to use the “free phone” that comes with a plan. Toss it out of the window after you receive it. Carriers are disabling features in these locked phones, they try to screw the consumers. Value your integrity & freedom and start saving money to buy an unlocked GSM phone (unfortunately the CDMA users can’t do anything about their disabled features, e.g. Verizon’s policy on Bluetooth PAN).
If you would like a full-featured smartphone, I would recommend the Nokia E50. It sells for less than $260 online and being a smartphone it will allow you to run native apps — not just the J2ME crap. If you don’t have that kind of money, you can get a Motorola L7 for $140 (my review). These two models I consider the best GSM phones for their price range.