fabricluvr,
Not a pain at all. It is just leaning up against the wall. The board is not always called "sound board", but if you tell the hardware store you want a 4x8 sheet of board that you can stick pins in, they should know what you are talking about. In our Home Depot it is all the way to the back of the lumber department, on a bottom shelf. I actually got the idea from the "Quilt in a Day" show. She covered hers with auto headliner fabric and it probably holds the blocks on much better, but I can't afford headliner material.