These are the steps to setup your smartphone to connect to lets say Cingular's WAP network with Dialup networking (DUN). This is also known as tethering.  I have the MediaNet unlimited plan and would recommend it for anyone doing this (don’t want a big cell phone bill).

I will use it via Bluetooth on my Windows Server 2k3 SP1 machine (should work on XP SP2 also)

Once you have your Bluetooth modem installed do the steps below

1. Open the BT modem from the control panel of the PC (Control Panel -> Phone and Modem Options -> Modems Tab ->Properties button)
2. Go to the Advanced tab and add (without quotes, case sensitive) "+CGDCONT=1,"IP","WAP.CINGULAR"
3. Save and close that

you can create a new DUN connection

1. Phone Number: *99#
2. Username: WAP@CINGULARGPRS.COM (this is case sensitive)
3. Password: CINGULAR1 (case Sensitive)

I got 115kb/s from my office.  Enjoy.  This was hacked together from data from a bunch of sites found using my Fav Search engine (will go nameless)