like shape it to a curve so it will stay with out being attached to something? i believe there is some sort of clamps/form/steam thing you can do, but that shouldn't be needed for a curved rail. you should be able to find a way to make a curved frame by cutting the wood the right way, and plywood/pvc should be able to stay shaped to a curve if its not to thick, the curve is not to sharp, and you attach it somehow.
Bumping Bush rocks balls!!!!
"No matter how much you shake and dance, the last 3 drops go in your pants." -Shane McConkey