Caught Ya Being Good!

I've seen this used in a few classrooms, and by using an incentive system instead of a punishment system, there seemed to be fewer problems in the classroom. When any of the teachers saw a student doing something good and right in the classroom, such as picking up their garbage without being asked, stacking someone elses chair, helping a friend in need, their name would go in the 'caught you being good' jar. At the end of the week (or how ever often you want) one, or two names are drawn and those students get to pick a prize out of the treasure chest.
In the classroom I was in, when student's were caught being good, they received a "Caughtcha". One of the teachers would fill out the caughtcha with the student's name, class and teacher, and what they did that earned them a caughtcha. At the end of the day, the caughtcha's were delivered to the principal and put into a jar. Every Friday, the principle would draw anywhere between five and ten names of students who were caught being good, and those student's got to go to the Principles Office and pick a prize from his special chest.
Now, sometimes, there does need to be a punishment system in place for those certain times when students are out of line, but with a good incentive system in place, students are more inclined to be on task and helpful in wanting of a prize.