Don't you love that warm, fuzzy feeling? The jar says: Do something kind and get a warm fuzzy. Put it in the jar. When the jar is full you get a class party! Can easily modify for home behaviors - positive reinforcement.
Team Building Activity: Human Caterpillar Wheel - All you need is lots of newspaper, tape, and time. Use teamwork skills to test and build the loop, and then again to navigate the vehicle from one spot to another!
Class Pet: Quiet Critters want to sit on your desk, see what you're doing, and get smarter. (Could remove them from the chatty students; those who still have their "critter" at the end of the "quiet" time could turn it in for a small reward.