I was gonna say the same thing about the GPRS vs 3G thing. But, it does work. I did the same thing with my SonyEricsson T637 and Miami. I've also used my T637 as a backup modem for my SMC Barricade 7008ABR.
Would have loved to use my K790a (EDGE) and K850i (3G,) but those went USB and there's no USB NDIS drivers for us Amigans.
usb modems should work without problems, they only need to be switched (look into cdcacm aros poseidon class) and then, one of interface can act as simple serial device with standard
http://en.wikipedia.org/wiki/Hayes_command_set
