Well put, Sally. Our get togethers are more like plant sharing parties. The swap tool lets us get some trading done ahead of time, leaving more time for socializing at the swap.
Everybody gets a labeled "drop spot" for their plants, and whatever they have put dibs on via the swap tool -- or via tree-mailed requests to those not using the tool -- is dropped in their spot as people arrive at the swap. There will still be plenty of trading & sharing & "pimping plants" on the day of the swap, too. Somehow it all works out and happy people go home with new-to-them plants.