I've thought a bit about the problem of the lower hook messing with the sail when it is fully raised. I think a hook that pivots could be created to fix this.

Think of a hook that can rotate, and has a stop to keep if from rotating further down than 90 degrees to the mast. It could be spring loaded to keep it rotated up against another stop, parallel to the mast and away from the sail when not in use. A small line from it down the mast would be all that would be needed to rotate it down so the ring could hook it - the pressure of the sail would then keep it against the stop. Let off the deployment line, pull the halyard to raise the sail and the hook would return to its position out of the way. If the spring idea is too much trouble, a second line could be added to stow it.

This wouldn't be a hard thing to create, and would make it easier to reef. If you make 'em to sell give me a split of the action...

Another thing I've thought of relates to the functionality of windsurfing sails sold by Multi-Sail (Randy Reynolds' company), in which the lower panels of the sails can be removed via zipper to make a smaller sail. On catamarans with full battens, this would seem to be an easy thing to do - zip off the lower panel leaving a smaller sail that could still have a proper downhaul and outhaul attachment. Roll up the zipped off portion and stow it on the tramp, or in a sail bag tube under the tramp.

I've always felt that it is a huge mistake that our boats don't have the capability to easily reduce sail area. I know we have all these wonderful technics for de-powering and tuning to handle the heavy stuff, but these things often create drag, and if you put a foot wrong you're in trouble. A sail plan properly configured for the conditions at hand would be faster and safer. I'm sure some purists will flame me on this one, so be it. I'll keep my belief that all cats should be able to roller furler their jibs and reef their mains (even if mine can't).