I've been looking for this bit of info for a while, because I keep getting asked about it. I did some scouting around and found this report on mobile internet enabled phones from back in August. It's a free PDF, go grab it. It's got some of the numbers I was looking for, and is summarized on this page at eMarketer.
The number I was looking for? 37% of American mobile phone users have an internet enabled phone, compared with 47% in Europe and almost 80% in Asia. That works out to around 60 million subs here in the U.S. The report also talks about various ways people use the data (only 1% are heavy data users) and points out that the cost of mobile data services is the number one reason people don't use them more often.
I wasn't able to go to the CTIA Wireless Mobile Entertainment seminar today because I got sick (another sore throat, bleh). I'm sure there was tons of great facts and insite to gather from the day's sessions. I'm seriously bummed I wasn't able to make it. And from what I've seen online, no one is blogging it either. Why is there such a disconnect between the wireless and wired worlds? Isn't it obvious to everyone that they're going to merge very soon now?