I always have trouble carrying numerous glasses back from the bar when it’s my round: there are never any trays.
Rather than make several trips, or stick my fingers in the tops of each beverage, today’s invention is glasses which interlock.
These would have slots and protuberant ‘keys’ in the sides which would allow a collection of drinks to be held together and then easily detached when safely deposited on a table.
This array could serve as a kind of tray in itself, allowing eg plates of food to be carted back on the upper surface.