These are the settings to get T-Mobile TZones to work.  Also note that these are the settings if you get the $5.99 web plan on your smartphone (which is not suppose to work ;)

GPRS settings:

Name: T-Zone GPRS

Connects to: WAP Network

Access point: wap.voicestream.com

User name: <blank>

Password: <blank>

Primary DNS: 216.155.165.50

Secondary DNS: 216.155.165.51

IP address: <blank>

 

Proxy: (leave the HTTP and SOCKS with guids, these are put in by ActiveSync)

Name: T-Zone Proxy

Connects from: WAP Network

Connects to: The Internet

Proxy (name:port): 216.155.165.50:8080

Type: HTTP

User name: <blank>

Password: <blank>

In advanced everything is automatic.

In IE under options:

Select network: WAP Network