The New York Times did a nice feature on cooking co-ops.
A cooking co-op, or dinner swap, is simply an agreement by two or more individuals or households to provide prepared meals for each other, according to a schedule. The goal is to reduce the time spent in the kitchen while increasing the quality and variety of the food eaten. It’s not a new idea — dinner co-ops have been around for year.
It works like this: Once a week, you cook a dish (chicken enchiladas, for instance), making enough to provide at least one serving for each adult member of the co-op. (Children can be assigned half or full portions, depending on ages and appetites.) Around the same time, your fellow co-op members are cooking large batches of their chosen dishes.
Read the whole Cooking Co-ops article.