Gybing with spinnaker :

Totally forget about sheeting the main, just make sure you keep good speed through the manouvre and let the main gybe itself. Just keep the spi tight and pulling in the initial stages of the gybe (sheet out only a little to compensate for the changing apparent wind), then let go in mid-gybe and quickly grap the new sheet and move over to the new hull pulling the new sheet behind you. The turn of the boat is never stopped everything is one smooth motion. The following stuff happens : you start to luff up and the main gybes itself, you turn around sit down and pull in the spi and get it drawing; then you look for the proper course again.

Like this you can gybe very quickly. I think some people also place their knee on the old spi sheet when grabbing the new spi sheet to prevent the spi from flapping.

Wouter