Homework Club is a way for students to become accountable for their assignments. Each month the class is given an incentive for completing all of their homework (lunch with the teacher, popcorn party, homework pass, etc.). If a student fails to turn in their homework, they must remove their number from the club. At the end of each month, the numbers remaining on the board receive that month's reward.
If your class doesn't have homework or you already have a system in place, use the club for rewarding excellent behavior.
Idea is based on Lesson with Laughter's Homework Club. Check out her blogpost: http://lessonswithlaughter.com/homework-club-freebie/