Surfing the Internet using your cellphone and Bluetooth
This tutorial is lifted from the Howardforums T-Mobile FAQ.
Credit goes to johnnysc22.
Phone settings: Use auto configure tool from T-Mobile or get the settings directly from T-Mobile. Remember to put in the proxy in your phone. Remember that if you have the $2.99, $4.99 or $5.99 T-Zones, you probably won't be able to access any site that uses https. You're good to go with http and IMAP/POP3. You need the $19.99 or $29.99 Total Internet to browse https and other blocked ports Cell Phone Accessories.
First pair your PDA to your cellphone, read the instructions on how to do this. Its pretty easy.
Set up bluetooth modem on PDA: 1. Turn Bluetooth on. 2. Go to Start - Settings - Connections. 3. Tap on "Add a new modem connection." 4. Choose a name for this connection, e.g. "T-Mobile GPRS" 5. Under "Select a modem", use the drop-down menu to select "Bluetooth Dialup Modem". 6. Tap next. 7. Enter the number you wish to dial; for GPRS, the number is *99#. 8. Tap next. 9. Tap on the "Advanced" Tab. 11. Change baud rate to "57600". 12. Uncheck "wait for dial tone before dialing." 13. Input extra dial-string command. Extra dial-string modem commands: +CGDCONT=1, "IP", "wap.voicestream.com" 14. Click OK in the top right hand corner. 15. Click "Finish".
Now Setup the proxy on you PDA: 1. Go back to settings -> connections 2. Tap on "manage existing connections" 3.You should see the connection you created in the above step, click on "Proxy Settings" tab 4. Check the box "This network uses a proxy server...." 5. Type in 188.8.131.52 6. Tap ok in the top right.
Now just use the Connection Manager to start the Dial-up networking and connect using the modem connection you made.
Source(s): Bluetooth solutions