Check out this article by the New York Times. Whoever thought what we were doing would be news-worthy? While they don't address actually getting together to cook, the article does mention a few set-ups for swapping meals. Maybe you can find a way to work for you.
I liked this quote:
“It always feels to me that you actually get more than you give in the co-op . . . and so the myth of it being too much work was rather quickly dispelled.”
It pretty much sums up how I feel about our co-op.