I live in Florida and I know many people in mobile jobs. When they can get a decent signal with their air-card, it is only comparable to dial-up.
I have also noticed an increase in mobile user on my site and I expect mobile grow maybe exponentially on a yearly basics at least for a while. I borrow my friends IPOD to look at my website from time to time and while I have a lot of fun getting it to work for me, the speed is still just (comparable to dial-up).
An interesting note about my dial up users (according to my Google Analytics they amount to a little less than 3%). They have the lowest bounce rate, most page visits and longest time on site. What's up with that? Where can I find more dial-up users?