The Economist recently published an article on what the future phone might look like. Here's a very interesting quote from the article on the concept of presence:
“When I try to make predictions, I don't look at what I see in the technical realm, I look at what I see in the social realm,” says Mr Norman. He has recently been investigating how children interact with each other and with technology. “They are never alone with their own thoughts,” he says. Instead, they listen to music while texting and talking with friends next to them. “We are learning that we never have to be away from people,” says Mr Norman.