noticed one of the crazy schemes last week while watching SEA-PHX board. 3 or 4 people in mountainview inspired "alaska airlines labs" shirts were describing a carry-on valet system. There were extra staff to keep track of carry ons and load them prior to pax boarding, above their respective seats. This way participants only had to saunter on and sit down. Looked like about half of the pax opted in. They were then assigned boarding groups, but not where it's a block of people in one part of the plane. Groups deliberately included people from throughout the cabin so that you iteratively loaded waves of pax, without creating intense congestion in a particular part of the a/c. seemed a good idea, though gate valet for carry-ons seems a tad problematic.