Mobile Pocket Projectors

This describes a mobile Pocket Projector, created by the head of the MIT Media Lab, Ramesh Raskar. I'm adding this here because it would be useful for a mobile Landmarks game.  Once the student/gamer finds the right location, several fake RFID tags could be posted in different directions, seen from the same spot or street intersection.

http://web.media.mit.edu/~raskar/pocket.html

This could be used to register whether the student/gamer had arrived at the right spot to see the landmark or view.  Also, they should take a picture of what they see and the software should be able to compare whether it's the same view, within a certain amount of leeway ("tolerance").  Using RFID tags posted on lampoles, etc. would pin down someone's success or failure quicker, because image recognition by computer software is still tricky.