When I first started going they did a class vs. teacher point system that would win them a free morning party on a Friday after a certain number was reached. If the teacher got more points than them they had to do silent reading instead of the party. I thought this was a clever idea because it motivates them to do good for more than just one day. They cant earn a party in a day it takes them a whole month so for a month they are trying their best.
The teacher also came up a with a pin system where they each have a pin on a board and if they are not listening they move a pin down and that results in 5 minutes of recess missed, then the next one is the whole recess, and eventually works down to meeting with parents. They can also move up and get rewards for doing good in the class. I really like this system for more of a personal reward/punishment if just one student is being bad and the rest of the class deserves a point for their party.
I can see now how hard it is to keep the whole classroom under the same reward/punishment when their is just one or two trouble students. Its important to have an alternative for those students. Both systems I thought were a great way to handle the classroom behavior.