This hint will allow you to use T-Mobile's WPA encrypted connection at T-Mobile hotspots. This is an update to this previous hint.
Open Network Preferences, select AirPort, click Advanced. In the Advanced section, click on the 802.1X pane, then click the 'Enable 802.1x Login' box. In Wireless Network, enter tmobile1x; under Authentication, check these: TTLS, PEAP, EAP-FAST, LEAP, and MD5. Now click OK.
Under Network name, select Join Other Network; in Network Name enter tmobile1x, and under Security, select WPA2 Enterprise. Finally, for 802.1X, select TTLS-PAP. For User Name, enter your T-Mobile Hotspot user name (what you'd enter on the login screen). For Password, enter your T-Mobile Hotspot password.
Now click Join, and you'll be connected and able to surf! NOTE: You will not need to login on a web page when you use this method.

