I have a simple suggestion for airline companies, designed to cut five minutes or so off every trip. Instead of boarding rows 20-40, line up passengers in order of row number. To simplify matters, have the numbers painted on the wall or the floor. Before boarding we all go to the squares with our row numbers on them. Then we file on board in order, everyone gets to his row, and everyone starts putting luggage up, sliding into seats, etc.
There are probably still more efficient versions of this, but the one I have just described seems entirely workable and would result in a significant reduction in the time to load a plane.