This is seriously one of the weirdest glitches I've ever seen...
First, get two controllers. Enter the story "Crystal Skull Part 1" and have Player be Indiana Jones while Player Two will be any other character you have. Use Indy's whip to capture Player 2 (Hold "B" and aim at Player 2) and then go o the place where the Airplane is. (If you haven't bought it already, BUY IT!!!) Go up to Player Two and pick him up by pressing "Z". Go up to the plane and have Player 2 press "C" to enter the Airplane.
If you pay close attention to what Indy is doing after this happens, you'll see that he's still in his Carrying Animation even though he's not holding Player 2. Do you know what's even sweeter? If Player 1 presses "B", Indy turns into an airplane! Turning our attention to Player 2, he will be hanging out of the window of the airplane. In fact, he's acting like he's still being carried! To get out of this glitch, have Player 2 Drop Out and everything should get back to normal.
Wikipedia: Tensile strength A measures of the force required to pull something »