Around here it's probably Verizon as they do have a higher speed service - not to be confused with High Speed - at up to 144k - 1/10-1/20 your cable speed. It runs over the cell system. I was debating it for the site but It's too expensive for me to justify right now.
Melissa found the wire and software on ebay for 20 bucks, I think verizon wanted 80 or something like that. We use it on weekends so it ends up being free because it just costs for the minutes used and our weekends are free. But it is painfully slow so we turn off pictures but it's still way slow compared to comcast cable.