You can get a card that slips right in the notebook's card slot. It's a dedicated wireless modem. Speeds are similar to dial up most places. A few big cities have higher speed networks.
Depending on what cell plan and what model phone you have you can also get a cable to hook your phone to the 'puter. Cell companies are discouraging this method because they want you to go with separate modem card -and separate bill- so they can charge you for that line too.
Gary