O. K., The way I understand it is that you can connect to the internet using an iPhone. Is this correct? I presume that this uses the same type of technology all cell phones use to connect to a phone line. Is this correct? So, the main question is why haven’t they built a laptop computer with the same capibility? Or have they?
They have; talk to your cell phone provider about a PCMCIA card or USB adaptor that will get on whatever their data network is called. I’ve seen them built in, but it’s an expensive option (the service costs about $50 / month), so it’s not very popular.
You can get laptops with built in wireless modems of all sorts. My wife has one. It has three radios, bluetooth, 802.11 and EVDO (this being verizon’s high speed data service.) There have been available for years. You need to buy service for the cell phone modems to work. You can also get cards to plug into a PC that does not have it built in.
You can also “tether” your computer to your phone (either wired or via Bluetooth) so that your phone acts as a modem. I used to to this with my Razr via Bluetooth. Although the iPhone has Bluetooth, it doesn’t allow tethering (yet).