[siglesias]

At least 50, by my reckoning. I'm thinking of doors, televisions, cups, windows, chairs, eyeglasses, automobiles, all sorts of things with coy simplistic descriptions that exist in innumerable variety of physical appearance.

[georgemcbay]

None of those things (with the arguable exception of eyeglasses) have practical benefits from being as small and light as possible while doing their job, so it isn't the same.

[siglesias]

But surely there are other design considerations and constraints that bind objects within these classes together.