I give out those small tickets used at the dollar movies or carnivals for good behavior, following classroom and hallway rules, being kind and courteous (saying thank you, bless you, etc.), sharing (without being asked), returning notes to/from parents, returning homework, ETC. The students are instructed to put their initials on the back, and to put them in a safe place. (One year, my third graders deposited and withdrew them from a class bank.) On Friday, we have a movie party, the students must first purchase a ticket to see the movie (6 tickets), then they may purchase popcorn, soda, candy, etc. with the rest. It sounds expensive, but I usually only purchased one pre-popped bag of popcorn, one liter of soda, and cheap/on-sale candy.