Gaucamole usually doesn't last long enough in our house to require saving. But when it does, the plastic wrap directly touching the surface is the best was to preserve it, as was stated by everyone else. I'm afraid that when you make it, you'd better be willing to eat it very soon. And remember, guacamole isn't just for dipping. You can put a spoonful on top of your chili, in your burrito, on top of Spanish Rice, in your taco, on your burgers, on your taco salads, etc. It's also great on tamales, and enchiladas. Why I've even been known to eat some off of my index finger, very tasty.
Seeeeeya; Goodweed of the North