I love the idea of a Soup Swap, and unfortunately I can't give credit where credit is due because I'm just not sure who is responsible for the idea originally.
The idea is a simple one really. Each participant makes a large batch of soup, and packages it in quart sized and freezer safe containers - one for each of the other participants. Then everyone gets together and trades their soup - each person going home with a variety of new soups to try.
I've recently hosted two Soup Swaps. The first was a gathering of 6 home cooks and their boyfriends, spouses, and partners. I hosted on a Sunday afternoon. I served several pitchers of Mojitos, and snacks. Each participant left with 6 handmade soups. For this one I requested that everyone also bring the recipe for the soup they had made so others could also add to their recipe collection.
This first swap was mostly a huge success and a lot of fun. The two caveats I took away from this first event where this: I hadn't requested that people make public what kind of soup they planned to bring and we ended up with three potato soups. Granted, they were all very different, one had bacon and cheese, another was potato leek, and one was plain old potato. We also agreed that a smaller group may have been better - 6 quarts is a lot of soup to make in a single batch.
The second soup swap was done with my crafting group. For a little over a year I have been meeting every other Sunday evening with a group of knitters and crocheters for dinner, wine, and crafting. At our most recent meeting we all brought soups for swapping. We were a smaller group, and everyone was only responsible for 4 quarts of soup, which indeed seemed more manageable. We also shared in advance what we planned to make and therefore had no duplicates.
The final inventory for my two soup swaps looked like this: Maryland Crab Soup, Grandma Woof's Potato Soup, Potato Leek Soup, Potato Soup, Lentil Collard Green Soup, Vegetarian Minestrone, Tomato Poblano Soup, Carrot Habenero Soup, Vegetarian Chili, Greek Lemon and Rice Soup, and a Vegetarian Gumbo.