presumably putting up pictures of people next to whom you would never ever want to sit on an aircraft.
One of the thigs I love about flying is sitting next to a total stranger and trying to start a conversation, if they seem disinterested I just talk anyway to really piss them off.
Just a little article I've got in my mind, but want to do it in a safe way, so I'm just playing around with it a bit.
Saying prayers just as you're about to take off is always a good one - it really freaks them out and guarantees they won't talk to you. Best to avoid it if you're sitting next to a nun or a Muslim cleric though.
Or taking a big steel bolt onto a rollercoaster and waving it in the air screaming "Stop! Stop!" when the rollercoaster starts.
Come out of Santas grotto with tears in your eyes telling the queue of kids, "oh my God santa is dead" then revel in the horror, screams and tears.
You can create the same effect by wandering round a children's zoo with a recently murdered rabbit under your arm.