I remember reading about a Brit who was on board a 154 in Ulan Bator or somesuch end of the earth place, waiting to depart when a guy, dressed in overalls, walked up and down the cabin clutching a large, greasy piece of equipment.
A few minutes later the captain announced over the PA that the equipment that had just been paraded throught the cabin was necessary for the onward flight and if the pax wished to continue the journey, they should consider stumping up about $100 each to buy it!
Here's a pic of the thrust reversers deployed before the wheels are fully in contact with the runway
