Here's what I was talking about last nite:
Grip the avocado gently on one side with one hand. With a large, sharp knife in the other hand, cut the avocado lengthwise around the seed. Open the two halves to expose the pit.
This is the tricky part. Use a weighty, sharp chef's knife. Holding the avocado half that contains the pit, whack the pit with the knife with enough force so that the knife edge wedges into the pit, but not so hard as to cut all the way through it. For safety, you can fold up a kitchen towel and use that to hold the avocado half. I generally just hold the avocado half and very gently whack it a few times, each with increasing pressure, until a cut is made in the pit sufficiently to twist the pit out. Getting the pressure just right takes a little practice. You could also use a spoon to scoop it out.
If you want to just mash it - mix it with some type of citrus juice then also dribble some over the top then cover it with plastic wrap, pressing the plastic wrap down on top of the avocado. The 'cado will react with oxygen & turn brown, which doesn't look very good.
*Testing for ripeness: To test for ripeness by cradling an avocado gently in your hand. Ripe fruit will yield will be firm, yet will yield to gentle pressure. If pressing leaves a dent, the avocado is very ripe and suitable for mashing. They are best served at room temperature.
Found this on the 'net too:
Freezing Avocadoes
You can freeze mashed fresh, ripe avocados if you want to have an "emergency supply" of avocados on hand for guacamole.
To freeze, mash the avocados with a fork. Add one teaspoon lime or lemon juice per avocado and mix well. The best way to freeze the prepared mashed avocados is to use a freeze-weight zip lock bag. Fill the bag with the mashed avocado. Remove the air from the bag and then zip closed and freeze.
Thaw the frozen avocados in the refrigerator or place the container in a bowl of cool water to accelerate thawing.
http://whatscookingamerica.net/avacado.htm