As a GIS professional I really enjoy seeing real world examples of applied GIS technology that quickly and easily educate.
I recently came across this cool example of a real-time Topographic map created using a children's sand box, likely an IR camera and projector.
The video does it more justice then I can describe, but shouldn't this be in every Science Center in America? With a few adjustments you could have very real discussions on the impacts of sea level rise on coastal communities and allow kids to play and learn. They did a great job with it. Great idea.