Another alternative is to use Verizon. Several of the newer Verizon GSM capable phones can connect to the internet via higher speed (180 kbps). Of course, Verizon charges for the high speed service, called National Access, but the folks in the InternetByCellPhone Yahoo group have discovered a back door that allows one to connect if you have the much more feature rich (and cheaper) Americas Choice plan and only get charged for the minutes used. Evening and weekends means a C-Brat favorite price: Free.
My phone (A LG VX-7000) is connected to the laptop via USB cable and the Mobile Office software connects wherever one can access a Verizon tower. No good roaming.
Caveats:
No support from Verizon. (They know it's going on but choose to ignore it.)
One MUST have a GSM capable phone. (If your phone has a color screen, it's probably GSM capable)
One must have Mobile Office software, phone drivers, and a cable. (Software and drivers are available at the Yahoo group site, cables on Ebay)
One must have a separate email provider. Hotmail Gmail or any provider that allows you to both send and receive from a foreign host.
It works great too, btw.