I am collecting some of the resources and materials that are helpful when teaching the basics of GIS to extend my current toolbox. Some of those I use myself when teaching introductory courses. I am looking for other hands-on materials (preferably, non-digital) that can help understand some of the GIS/geography related concepts such as projections, spatial analysis, and others.
Probably one of the most famous examples is a trick with an orange peel when a navel orange is being peeled to demonstrate the projection from a globe to a flat map. National Geographic has detailed instructions on this excellent tutorial along with other materials for constructing 3D models of Earth from paper (read more about Investigating Map Projections).
I also use an overhead projector for demonstrating with transparent plastic sheets how a route can be drawn (with a pen) while avoiding forbidden territories over multiple layers (conceptually, path analysis and geographic overlay illustrations). Great guidelines are available in the book The Really Practical Guide to Primary Geography.
What is great about these examples is that students can try this themselves - to see the holes in the orange peel and to see how hard it is to find a route taking into consideration the areas of multiple sheet layers.
What are other known hands-on materials that can help illustrate spatial/GIS concepts? Things that are related to computer science (such as database management) that have something related to geography would also fit.