cravaus

For T-Mobile you need the $4 T-Zones service and then....

Setting up the connection
On the PDA, tap on the Bluetooth icon in the lower right corner. Tap on Turn Bluetooth ON.
Tap on the Bluetooth icon again, and tap on Bluetooth Manager.
Tap on New, and then tap on Connect.
Tap to select Connect to the Internet.
Tap on Next.
Tick to select Connect via a dial-up devicesuch as a cellular phone or a shared modem connected to a computer .
Tap on Next.
Tap on .
Once the handset is found, tap on the icon representing the handset.
Type T-Mobile GPRS for the Connection name .
Tap on Finish.
For the connection to use, tap on New Connection, and then tap on ok in the upper corner.
Type T-Mobile GPRS for the Connection Name .
Type *99# for the Phone number, and then tap on ok.
On the handset, you will be prompted to Bond with the PDA, press the YES button to continue.
Enter a Bluetooth Passkey (1234 for example) and press the ok button.
On the PDA, type in the same Passkey as you entered on the handset and then tap on OK.
Tap on Cancel.
Tap on Start, Settings and then tap on the Connections tab.
Tap on the Connections icon.
Tap on the Advanced tab.
Tap on Select Networks.
From the top drop down menu, tap to select Bluetooth Work Settings .
Tap on ok.
Tap on the Tasks tab.
Tap on Manage existing connections under Bluetooth Settings.
Tap to select T-Mobile GPRS and then tap on the Edit button.
Tap Next twice and then tap on the Advanced button.
In the Extra dial-string modem commands field, type +cgdcont=1,,"wap.voicestream.com".
Tap on ok and then tap on Finish.
Setup your Proxy by clicking the proxy tab in Bluetooth Work Settings
Thit the Advanced button
proxy 216.155.165.50
port 8080
Set each type to these settings
Click ok four times and you are out
Making the connection
On the PDA, return to the Bluetooth Manager.
Tap and hold on T-Mobile GPRS.
Tap to select Connect.
Tap to select T-Mobile GPRS and tap ok .
Ensure the User name, Password and Domain fields are left blank.
Tap on OK.

I think the source of these directions was from a site called MotoModers. It may have come from this site. I do not recall.