iPhone stats
I'm with Rui on the recent iPhone stats - sure, they show iPhone users doing a lot of web surfing; but whether this is because the iPhone causes its owners to get online more, or whether the kinds of folks who spend half their lives online already are buying iPhones is a different matter.
Anecdotally, it's the latter. I don't know a single normal person who's bought one (no Jack, not even you). Demographically this audience might be the same as the smartphone audience (high earning 18-34s) but I'd wager they're more inclined to come from a tech/media industry background.