The idea and most of the poster downloads are for free at Rick Morris's website on classroom management (http://www.newmanagement.com/main/classroom-gestures.html) .
I added a few that I would like in my classroom. I laminate them and put them next to my rules.
I recently added a new set of the exact same ones but with a border so they are not so plain. If you would like me to add any new sign let me know and I will be happy to make it for you.
*Now updated with restroom symbol!