I'm in the same boat as you: looking for cellular internet access for my laptop on the road.
Here's what I've put together. A Smartphone that has Dial Up Networking (DUN) capability can connect your computer to the cellular network (tethering).
I've been looking at Verizon's specifics for this, it is probably different for other carriers. Verizon has a page discussing high-speed internet access over Bluetooth, http://support.vzw.com/how_to_use/bt_dial_up.html. There are two PDF files linked there that show which handsets support DUN profiles. I presume that most phones will support via USB data cable as well as Bluetooth.
It looks like non-Smartphones will support DUN as well, but I think you have to purchase a dedicated data package to get high-speed access. It will look a little fishy streaming video over a RAZR. Apparently, you can connect at 14.4k to your own ISP for the cost of your plan minutes, though.
Hope this helps. Anyone who knows more, feel free to correct me.
I can't figure out the answer to this one:
If I want to use my Laptop on the road to get on the Internet, can I purchase a SmartPhone/PDA, plug it into my computer and browse the internet through the phone
do I need to purchase I wireless/cell pc card for my computer?
Any help is greatly appreciated!