I used to be able to tell my computer that dialing *99# on whatever modem was on the other end of the Bluetooth port was a really great idea because there would be a PPP link waiting for it. My computer would try to do so, and the phone would know that what it really should do was switch on the GPRS radio, get on that network and hook up to a special datastream I had told it would be at wap.voicestream.com. Then the datastream should be passed back to the computer just as if it was a standard data-call. The stream would produce a PPP sequence, the computer would follow it, and find itself with an IP pipe with DHCP and all, which was actually running over the GPRS network at 56k.
Well, my phone is now on the KPN mobile network, and this still works. For about 2000 bytes. Then somehow no packets come through to the computer anymore. That is it. Since T-Mobile (the former VoiceStream) has been locking down its data access points, I can't help thinking they are responsible for us losing that facility. I asked my father for his settings and am now using my mobile phone as a straight modem over Bluetooth. Except that you can't do good data over GSM. Incredibly slow rate. Feels like 9k6. I don't even want to think about the connection charges. But I have to check my work e-mail.