What Cool Tools best demonstrate the principles of Buckminster Fuller?

What tools are most instructive to show Bucky's ideas? As an example, I liked the Perky-Pet Ant Guard I noted in my review of Permethrin on April 7:

1. The design is functional: the toxin is located in a place where only ants should ever encounter it.
2. The toxin is protected from sun, wind, and rain; the time period of its efficacy wil be maximized.

One could say that, by its design, this product does more with less -- one of Bucky's favorite principles.