http://www.blackberryforums.com/showthread.php?s=0bd4aad41350ca919880c3f4e4ca229d&t=2019
The URL is a link to a thread that explains how to turn your blackberry into a modem for your laptop.
My work computer is the epitomy of shit - Dell Latitude with like 128MB of RAM and .01MB video card.
There are no wireless networks that I can access with my dual core macdaddy personal laptop in my office so I upgraded from the 7100t to the 8700g (i use T-mobile) and am now connected via the T-mobile edge network (3-5x faster than standard wireless connection).
YAHOO!!!! Its a 115200kbs connection..not great, but not bad all things considering....