I've got two in mind. One, in an old article by James, I saw this image
[img]http://farm3.static.flickr.com/2609/4114152158_915b98b915_o.jpg[/img]
illustrating pennant reefing of a Wharram wingsail. This would appear to have the [b]enormous[/b] benefit of keeping the mainsail under complete control while in the act of reefing. This could also be used on a jib with reef points. Do you suppose there are any disadvantages, ie, interruption of the air flow at the leech of the sail, due to the cleats and pennants?

Two, it occurred to me that using a double block rather than a single block for the mainsheet traveler, I could use the second sheave to run a line with a snapshackle to the desired reef grommet. This line would run to a camcleat and would also keep the main under control while I transferred the mainsheet's shackle to the reef grommet. This would appear to be the simpler of the two systems, and one I could test without putting holes in the sail.

What do you think, sailors?