If you are going to make your mobile site have a lot of "bells and whistles" like a "regular" site then yes you are going to have to make different versions for some of the OS of the different phones.
I eliminated that and went with the K.I.S.S. method for our mobile site.
I figure that someone viewing claudia-marie.com on a phone will 9 times out of 10 be showing it to their buddies. So I kept it real simple and just gave them the "meat" of the tour and members areas.
Since their login works for both the mobile version and "regular" version...they spend most of their time on the "regular" anyway.
So bottom line is...cm's site works on all phones so far. One version. And it has definitely made sales. And that is "found money" that I wouldn't have had otherwise.
EDIT: Having said that...the countdown is on for somebody to tell me it doesn't work on a phone I didn't think of lol