I dunno... being an iPhone user for 2 years now I'm fast on the keyboard -- really fast and accurate. I also own a BB for work and I find typing on it to be quite a chore these days. I think there will come a time when people really have to re-evaluate the bad rap the iPhone keyboard gets. I admit it's probably not for everyone but lots of iPhone users are very quick and accurate with it. I suspect humans can adapt to almost any type of input/control system with enough practice.
if you have larger fingers, or long nails (for ladies), then you are going to have trouble with the iphone keyboard.
Sure, you will get used to it, and be decent at some point after lots of practice, but i still find the BB Bold/ old Curve keyboards the best in mobile keyboards.
And I work with Mobile devices, so i have tried 10s of them.
That's funny. Judging from popular gadget sizing, I've apparently got fairly large hands (e.g. I was mystified when I found out people hated the original XBox controller. I thought it was perfect).
And I do far better on the iPhone keyboard than Treo/Pearl/etc. The landscape enV and BB Bold are easier for me to hit keys accurately with, but the auto-correction on the iphone more than makes up for the added errors.
I could see a physical keyboard with iPhone-caliber auto-correction being a superior choice. But for actual use with these big grubby mitts, among devices currently available, I find the iPhone to be way out front.