I saw this in a first grade class and liked the idea. The teacher said she purchased it at Walmart for $9. She said to go to the automotive section and ask for a mechanics drip pan.
She backs her behavior sticks with magnets and the students move them around but I could see it being used in a variety of different ways. You can make your own magnetic poetry and have students use it in a center. You could use it put the unit vocabulary word of the day on it. I really thought someone could get creative with its use.