Plonking your butt onto seat 1A while deftly asking the chief purser Excuse me my man, but would you so kindly place my backpack in the overhead compartment would not work. A list of passengers is typically kept in the first class galley, so that the flight attendants can address the passengers by name, and identify any economy class yoiks impersonating stuffy dowagers.

If the flight is full in economy class, a better strategy is to see if there is anything wrong with your allocated seat. Seat won't recline ? Is your neighbour offensive ? Is the headphone jack stuffed with chewing gum ? Don't stuff it yourself - they will know it was you coz the gum will be soft. The best thing to do if you can't find anything wrong is to pretend the audio unit is broken anyway. Try three different headphones and shrug your shoulders, looking mildly frustrated that you will be flying LAX to Heathrow with bugger all to do but spot cirrostratus clouds. With any luck the flight attendant will take your story at face value (rather than lean over up to two other passengers to check the unit), and see if there are any seats up the front.

Contemplate exactly how many rosaries this will cost you as you sip Chivas Regal up front. Or consider it pay back for the time the airline stranded you for eight hours in Jakarta.

I was down to -1 rep until I added that last sentence in. Then my rep skyrocketed upwards.