Granted, I bought a used 3GS, so it's certainly not cutting edge, but for me it's pretty exciting.
As I've been learning the ropes, I've been tickled by all the times the iPhone has done exactly what I wanted it to without me having to tell it. So I went to set up the weather app. I was thinking it'd be cool to enter in some of the other locations I care about so I could see what the weather was like there. I went to check the list of other locations and the first one was Cupertino, California.
"How did it know I grew up in Cupertino???" I gasped. I was slightly creeped out.
And then I realized. Oh right. Apple headquarters is in Cupertino. It's not that my iPhone knows I'm from Cupertino. My iPhone and I just have the same hometown! You'd think that having grown up with mostly children of Apple employees, I would have immediately realized that. But I guess I'm still a little iPhone naive ;)