Display many photos with an old frame, wire, and clothespins. PERFECT use for the huge frame I just took apart for the girls hair bow holder! (instead use coloring for clothespins and frame! Glitta it up)
Like shipping pallets, wooden cable spools are another item that is usually found for free on Craigslist. Since cable spools are limited by their shape there are fewer repurposing options, but they make a great coffee table bookcase.