I've got one of those scooter cases that fits in the overhead compartment. Its great for those long walkways that we all experience. I'm a responsible 'driver' and only scoot when there is plenty of space and I'm less of a hazard than those electric buggies. I've used it a lot with no problem at countless airports on three continents, apart from the fact that it attracts some looks. However, once at LGW I was going over the empty skybridge walking area. I passed an unidentifiable official who was on the moving walkway who shouted at me to walk only or else he would ensure I would not be allowed to fly and would be banned from the airport.