Sprint sells a CF card modem that will allow you to access their high-speed network internet access. Unlimited access will be about 120.00 per month
Check it out at
http://www.sprintpcs.com
The compactflash modem is fine if you want to be plugged into a phone jack and don't mind the slooooooow speed. You'll also want to have an 800 number or else you may have to find local dial-up access whenever you travel out of town.