I have been using a Verizon cell phone connected to the RS232 of my laptop since 2001.
At that time it cost me $25 to buy the cable and software (which also compress the data) from Verizon. When connected to a digital tower, I can do everything on the internet in my motorhome as in my home. Except, at home I have Roadrunner cable which is much faster than the 14.4 KBPS of my cell phone connection. I do not pay anything extra for the laptop connection.
I have a very basic service (300 minutes prime time, 1500 minutes after 9 and weekends) which may not be available anymore. Using this connection I do not have to worry about telephone numbers. Before roadrunner, I was connected to MSN as a provider and that also worked great.
The slow data rate teaches you patience. I up load all my pictures to my WebSite, mekkerfest.com, using this connection, along with e-mail, bill paying, and monitoring the stock market. But I am sure that by now there are much faster and better connections to the Web using the USB.
I am happy with what I have ($35 per month for the cell phone and the data interface) so I do not plan on looking into something faster. I still use Office 97! Why change?