It's a neat thing to do. I got picked a few years ago. This trip, I got to be an extra in the backlot tour. I was assigned to the PT boat as a deck hand (didn't want to be in the engine room chair!). Still got plenty wet from the air cannons, though. One thing they tell you, the blue jacket and pants they give you are water RESISTANT, not water PROOF! The other 3 people in the show with me hadn't seen it before, so they were caught off guard, especially the poor woman from England who got assigned to the chair!