My first encounter with mobile phone invisibility -- the ability of the MP to shield and isolate the user from all those other people in a 3 foot range to whom the caller is NOT speaking -- occurred in a two stall women's bathroom in a restaurant. The woman in the next stall asked me quite clearly if they had installed the carpet yet. I said, "I beg your pardon?" She said, "They were supposed to come this afternoon, and you know Mother's going to have a shit fit if it isn't done by Friday."
I said, "I beg your pardon, are you talking to me?", a question she never bothered to answer. She simply ignored me and continued her conversation. It was bizarre.
The last time I was in downtown Portland (OR) -- about a week ago, it seemed like one in ten of the pedestrians were talking on their cellphones.
If this is the future, I don't think I like it.