Other kind of feet like... wire record racks! Remember those? They also had spherical feet, same design! And, and, and (I'm on a roll now) wire dish racks! Yay, four uses!
Yes magazine racks - that can be the fourth thing I didn't mention when I said there were four things but only listed 3!
I spotted another thing in my house with them - white this time. It's a perfectly modern hang-on-door coat rack of 4 hooks! The balls on that are quite big - probably in the 20mm region. And the hooks they are on the end of could well be 6mm - they're not thin! Don't forget it's not just strength - it's look and feel.
I had another thought - little handles for little hands. Toys with sliding pieces where you hold the little knob. Or puzzle pieces to lift out. Or little drawers. Look in any shopping mall with a play area and I bet you spot these things (in larger sizes). They could just be pushed onto a dowel (well, glued anyway).
