Yesterday I was over installing some software in our geography department, and they had something really cool. It was an augmented reality sandbox. Basically a sandbox with a projector aimed down at it, and sensors and software to do things like overlay contour lines and simulate the flow of water over the landscape.
Here's a video of one:
Aside from just being neat, in the future this might be a good tool for explaining permaculture concepts to people in a classroom setting.