Max Collins, (the man many of a cetain age will remember as the best trumpet player in the world who didn't need a trumpet) used to, pre flight, note at what window the most likely passenger was sitting. He had a small skeleton on a piece of string, the string carefully marked so he'd know when the skeleton was directly over the chosen one's window.
I understand it got some rather amusing results in the cruise - but I never worked out how he kept the skeleton or the string from fouling the #1 prop.