Re: I've personally measured 61,750ish volts on an empty, unused Styrofoam coffee cup
Strictly, voltages are (differences) measured *between* things, not on them. The relevant electrical property on the cup would have been a charge (measured in Coulombs). (Edit: hmm, I suppose you might e.g. also measure the electrical field near the cup surface, but that's volts/meter...)
Do we need a Reg unit of charge? On the basis of the comments here, we could either go with the cup thing, or something about nylon dresses.