Timbo, the windsurfers have experimented with this for years. There was something called camber inducers for a while, battens that split at the mast with a double layer of cloth there. When tacking/jibing, the battens popped over by themself. I think the same was tried on some older C-class sails, but I think the technology is pretty much dead now as it is not as efficient as a wingmast+soft sail combo or rigid wing.
For fun, why not try a 50%wingmast with a soft sail as flap <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" /> Would be fun to sail, probably, but a beast on the beach.