SonyEriccson s710a:
Found this over on HowardForums.com.
Special thanks to beavis4ever for the find!
Ok, I had a problem doing this too, and nobody replied. It took me a couple months to figure this out.
First pair the 2 devices.
Next go in to Settings on PDA.
Go to the Connections tab.
Double click connections and select "Add a new modem connection."
Enter a name for you connection. (ie Cingular)
Under "select a modem" pick Bluetooth Dialup Modem. Then hit next.
Enter *99***1# for your phone number and click next.
For username enter
WAP@CINGULARGPRS.COM and password CINGULAR1.
Then click Advanced, I changed baud rate to max 115200.
Uncheck "Wait for dial tone before dialing."
Now, the part I had to research, the init string. Enter Z&f+CGDCONT=1,"IP","WAP.CINGULAR" where it says Extra dial-stringmodem commands. Leave all other Tabs at default and hit OK.
Click finish and you are all setup.