I had this brainstorm yesterday as I passed by the custodians’ workshop. They were throwing away old discolored 2′ x 2′ ceiling tiles, and I was looking for a splash of color for my classroom walls. I’m going to throw a bit of fabric over them, staple it around to the back, and hang them on my walls as bulletin boards!
You can buy bulletin board in Home Depot, too; it even comes in 2×2′ and 2×4′ squares, or they’ll cut it down from a 4×8′ sheet for you. It’s also called “Sound Board”, as it will reduce noise.