Creepy as hell, but if it could use face recognition and give you data about people that would be some next level stuff.
Nothing else, it doesn't have to bring up their facebook profile, twitter feed or anything else. It could even rely simply on entries I've entered myself, knowing someone before they've introduced themselves would be creepy. But just something so that when people remember me I don't stand like a dick because I can't recognise their face would be nice.