It's time to create some virtual reality or augmented reality.
Not only new methods of user interactions are possible using vision besed tracking.
For 2D tracking the reacTIVision project is really interesting.
RPG application can be a virtual tabletop controlled by "fiducial token ID".
It could be a nice integration for applications like MapTools.
For now installed the application and tested successfully.
Will have to find something for 3D tracking and eye tracking.
By the way it's an open source project.