Freezing Eggplant

Step 1 - Get yer eggplant!
Start with fresh eggplant - as fresh as you can get. If there is a delay between harvesting and freezing, put it in the refrigerator or put ice on it. Harvest before the seeds become mature and when color is still uniformly dark. Some varieties and size freeze better than others. Like many vegetables, eggplants do become soft after freezing and shed water as the cell walls rupture. The traditional black varieties hold up a bit better than the purple Chinese and Thai types, but in many dishes (like Indian baigan bharta) it won't matter.
Step 2 - Wash the eggplant!
I'm sure you can figure out how to rinse the eggplant in plain cold water.

Step 3 - Peel and slice the eggplant
Just take a sharp knife and cut of both ends (about 1/4 of an inch, or half the width of an average woman's little finger). Then peel the eggplant - an ordinary vegetable peeler works best.
Step 4 - Slice the eggplant
Slice 1/3-inch thick slices.
Prepare quickly, (if you leave it sit cut for more than a half hour, it will start to discolor). Do enough eggplant for one blanching at a time.

Step 5 - Get the pots ready
Get the pot of boiling water ready (about 2/3 filled), and add 1/2 cup of lemon juice to each gallon of water. Also get a LARGE bowl of ice and cold water ready to receive the eggplant after blanching.

Step 6 - Blanch the eggplant.
All fruits and vegetables contain enzymes and bacteria that, over time, break down the destroy nutrients and change the color, flavor, and texture of food during frozen storage. eggplant requires a brief heat treatment, called blanching, in boiling water or steam, to destroy the enzymes before freezing. Cook (blanch) the eggplant for 4 minutes.
Begin counting the blanching time as soon as you place the eggplant in the boiling water. Cover the kettle and boil at a high temperature for the required length of time. You may use the same blanching water several times (up to 5). Be sure to add more water from time to time to keep the water level at the required height.

Step 7 - Cool the eggplant
Remove the eggplants from the boiling water with a slotted spoon and place in i ce water to cool for about 5 minutes (until cold).
Cooling them quickly prevents overcooking. Keep adding more ice as needed.
Drain thoroughly 2 or 3 minutes)

Step 7 - Bag the eggplant
I love the FoodSavers (see this page for more information) with their vacuum sealing! I am not paid by them, but these things really work. If you don't have one, ziploc bags work, too, but it is hard to get as much air out of the bags. remove the air to prevent drying and freezer burn. TIP: If you don't own a vacuum food sealer to freeze foods, place food in a Ziploc bags, zip the top shut but leave enough space to insert the tip of a soda straw. When straw is in place, remove air by sucking the air out. To remove straw, press straw closed where inserted and finish pressing the bag closed as you remove straw.
If you want slices for frying later; pack the drained slices with plastic wrap between slices. That will help to keep them from sticking to each other.
Note:
If the eggplant is very wet, after draining it, just put it in the food saver bag and freeze it (unsealed and upright) in your freezer. THEN, several hours later or the next day, when it is frozen, you can seal it with no mess!
Step 8 - Done!
Pop them into the freezer, on the quick freeze shelf, if you have one!

Source:
http://www.pickyourown.org/freezingeggplant.htm