This is the method I use. I just got some really inexpensive vynal(sp) tablecloths at the discount dollar store for really cheap and used thumbtacks to put them on the wall. They have a flannel-like back (maybe more like batting) that makes my blocks stick quite well. I don't know what I would do without my design wall and it cost practically nothing. Can't get any better than that!
Doug in Akron, Ohio