I have a large design wall that I hang when needed but I made a smaller one out of a foam presentation board (2x3) and covered it with flannel to use to illustrate a quilt block that I was doing a program for guild. I'm surprised at how much I use that board at home too. It's certainly not appropriate for a quilt but for smaller projects or to keep blocks out of the way it is just the ticket.
Thanks for the suggestion on headliner fabric. What a great idea. It would have never occurred to me.