T-Mobile USA has a $5.99 data plan called T-Zones. This can be used on the iPhone as the data plan in place of the $19.99 total internet or black berrry type plans. With T-Zones, some of the apps (such as YouTube) may not work over EDGE since T-Mobile may block some ports, but it works for most stuff.

To use T-Zones, follow these steps:

• Subscribe to T-Zones package with T-Mobile. (Note it usually takes a couple hours to activate, it may take a day).
• Install the T-Zones hack in installer from the BigBoss Cydia repository.
• When the install has completed, reboot the phone by holding power, sliding to power off, and turning it back on.
• Test by disabling Wi-Fi and going to www.google.com. If it errors out, refresh the page.
• If does not work, verify your EDGE settings in settings, general, network, EDGE to be APN: wap.voicestream.com and user/password are blank.

Most errors are caused by TMobile not activating your T-Zones package even though they said they did.