This is a great system to use in your class and super easy to get started. Students recognize others' positive behaviour and write it on a shout out card. They put it in a jar and at the end of the week we read them. I have a shout out tally going in my class and when everyone is showing expected behaviour I add a tally; a tally can also be taken away. The number of tally marks at the end of the week determines how many shout outs I will choose for prizes.
*I have also heard of people doing this to recognize staff members!