I have a friend who also teaches fourth grade science who plays vocabulary bingo with her students a lot (see earlier post on playing/setting up vocabulary BINGO). She decided to use poster board and make a giant BINGO board to put on her wall for each of the units of study. When she plays with her students she uses sticky pad paper to cover up the words she has already called.
The poster serves two purposes for her
1. It is her vocabulary word wall for the unit
2. She can use it to keep track of what she has already called during a game
I have not seen it in use but I really liked her cute board and drawings (she is WAY more artistically gifted then I am :)