Pebbles in a Glass
Jennifer Silverman put together a neat lesson based on the fable of The Thirst Crow.
http://bit.ly/ggbcrow
It uses GeoGebra statistics functions to record data and make a symbolic model.
That got me thinking about how to model the experiment in GeoGebra. Although it is clearly better to do the activity with water and stones, it was a good challenge to figure out how to model it. Volume of spheres and cylinders and more.