After about four hours of screwing around with my Powerbook, a USB cable and a Motorola T720 I managed to get GPRS browsing working through the phone on Rogers Wireless.
So score one for me. I then sold the package to a guy from the Kelowna Capital News, so score two for me. I also got to spend four hours of work sitting at home in my underwear so score three for me.
So if you're wanting to use a Motorola phone via USB on Rogers with a Powerbook, drop me an email and I might (might) be able to help you out. It is kind of tricky and I had to download a $20 program to write a modem script for me, but I assume it'll work for any phone now.
I have to open tomorrow, so I probably shouldn't still be awake.