Augmented Reality?

So, it's been on my mind all week as I attended this conference. If you're not familiar with augmented reality, it's basically a way to use a mobile device's camera that adds information to the screen on whatever the user is looking at through the camera. Examples - heads-up displays on cars or fighter planes. The little yellow first down line that you see on football broadcasts. Could we implement augmented reality in the library? *Should* we try this at the library? What kind of information could we put up that would be useful? I could imagine using it to direct a user to a call number, or a specific section of the library. Maybe to show a student where a librarian's office is, and the contact information for that person. Stuff like that. Thoughts?