I was reminded of one earlier: Roll-aboards.
Some of the ones that people are trying to stuff into the overhead bins of aircraft are bigger than the suitcase I've stuck in the hold. Not to mention that if they need a bag that big, they're not going wherever for a couple of days, so how did they get all their toiletries through security?

And another one for flying, boarding.
If you really want to get the flight out quickly, organise the boarding to put people on at the back and sides first, not start with the front so that everyone else has to queue whilst some muppet takes five minutes to stow their oversized and overweight carry on, sit down and let one person past, then get up again, get a book out, sit down, get up for a pen, sit down...