Self-organisation is one of the most fascinating phenomomena, especially when the rules are simple and the behaviour useful.
Today’s invention ticks at least one of these boxes.
It is a linear tray for glasses.
A handle contains a hairdryer. This is attached to an airtrack of the kind used in Physics classroom demonstrations.
When one of the glasses, which have magnets on either end of their bases, is removed, the fan senses this and instantly switches on. This activates the air track, so that the remaining glasses move, under the action of the repelling magnets, so as to redistribute themselves evenly along the length of the track.
This ensures that the centre of mass of the glasses is always approximately just above the handle, making serving easier.
(A short circular track would be possible too).