I have a friend who uses a flannel sheet on a frame made of PVC pipe. It sets up and takes down easily, is portable and very cheap. Go down to Home Depot and buy four 8" sections of 1" PVC pipe and four 90° elbows. Dig up an old king or queen size flannel sheet, sew some casings in it, stick the pipe in the casings, put the pipe together with the elbows, and viola! a portable design wall.