I'd have a "best guest ever" contest based on a points-system. Everytime somebody is observed being courteous to others, or helping out in a good way, they earn points good toward epic, mystery prizes awarded at the end of the day, announced on a popular radio station or something. So like at, I dunno, Speedway or something, they can check their 'point balance' on line or something. Heck, there can even be points for buying food, playing midway games, or even attending certain attractions. There can be like, mega pointbusters for getting caught line-jumping, POVing, flashmobbing the Carousel, or shouting obscenities and stuff.
Well, it looks good on paper, anyway...