pickles and ketchups--On Fridays, place them on the board. Anyone who has turned in all of their assignments is a "pickle" so write their name under the pickle sign. Anyone who is missing an assignment has their name placed under the ketchup bottle. Pickles can "pick" a fun game or activity, while "ketchups" catch up on missing work. It is amazing how quickly assignments come in.
"To teaching friends: I use this in high school as a formative assessment before moving on. I don't have a poster or anything, but it really helps you get a grasp on where the class stands on a tough concept." I might make a poster!!!