bc41129,
The easy answer is to buy a data cable and use your cell as a modem.
SupplyNet carries a mess of them for the Prism, which are all about $40. If you have a dial-up ISP you'll just burn cell minutes. If you have a data plan with your wireless, which I'm doubting if you're on a pay-as-you-go program, then you'd just pay the data rate.
There's a reason OmniSky went out of bizness...great & cheap services tend to do that.