Board Earlier
Purely from an observant passenger point of view, and fully understanding this would not be possible on short haul ops - my solution is to board pax earlier.
How many times are we sat in a departure lounge for ages looking at the plane waiting to board with 10 mins to go before scheduled departure time. then the usual anouncements and the scrum begins.
I know the do-gooders here will go on about preparing the cabin etc, but allow more time and let passengers drift on as they arrive at the gate. I have experienced this with a far eastern airline and IT WORKS. I know the purists will go on about passengers getting in the way of cabin staff etc but we should not loose sight of what we are trying to achieve.
Long Haul aircraft are often at the gate with at least a couple of hours to go before departure, so rather than que pax in a gate allow them to drift onto the aircraft as they arrive - works on trains, we don't have to be coralled in a gate to get on them!
Should cause a stir amongst the die hards - but trying to think out of the box here