One option is
EVDO. As mentioned in that article you can get a USB modem, which can be used with a laptop or desktop or a special router. There are other providers; I just picked this article to introduce you to the type of service.
Depending on your cell phone plan and phone you can use the phone sorta like a dial-up modem for internet access with a computer.
Either will probably require a 2-year commitment. I have no experience with either; guess that the EVDO is the better option.
Here is some information about
T-Mobile data plans.