Editor's Note: I remember going to a demonstration of virtual tagging technology at the Kihara Research Center in Tokyo several years back, and the researchers frankly weren't quite sure what to do with the tech at the time. They showed us a demo where we had IR transmitters in our visitor badges, and when they pointed their video camera at us, a virtual business card popped up on the screen. One of the reasons they had problems finding something useful to do with the tech at the time was that the user-level tech wasn't quite ready. Now it is.