BleepingComputer.com: The rundown for using a cell phone as a modem?

So I came here first to get schooled on how to do this.

I have a Motorola Razr...not sure of the version.
I have service through Cricket, but I don't have an internet plan.
This phone has been flashed.

What do I need to use this phone as a modem to connect to the internet with my laptop? Is it even possible on a flashed phone? And do I need to get an internet plan from Cricket first?

I figure that I could use the phone 'as is' as a dial-up type thing, but that hasn't worked so far. I just need a little direction and for someone to shine some light for me. Thanks guys/gals/things!