[ECONORAM]

I have considering doing this very thing. Dumping my home DSL and POTS in favor of using my 3G internet via my mobile phone. If you have Windblows Mobile 6, there should be a program buried in the Windows folder called "Internet Sharing". When you enable this and connect via the USB cable to your computer, you can surf the Internet like normal. I had to do it for a few days when I moved and we did not have phone service yet... I am keeping my POTS/DSL at present because I also have Dishnetwork, and keeping my tuner plugged into a phone line saves me a few bucks a month, and expedites service. I also keep it for my current position at work...
I was wondering if a similar service exists in the Iphone. If so, I will be super tempted to dump POTS/DSL, even though I would have to buy out the rest of my contract...
[edit[ you can make a shortcut to the program by doing a copy then paste into the programs folder. This tip I got from xda developers...