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.
"Have you filled a bucket today?" Teaching how to be a bucket filler. Gave out "buckets" with "warm and fuzzies" to the class & made classmates write a nice note to their neighbor to put in each other's bucket.