I was reading this post on Slashfood, where the author wistfully remembers before the age of the internets, when people would keep cookbooks, and write annotations on the edges of recipes to keep track of modifications, essentially preserving a history of how the recipe got adapted to a family.
And I thought - what we need is a concurrent versioning system for the kitchen!
Something that keeps the history of the recipes and their edits in place. WikiCipes? Heck, if the group is small enough, this could be done in Google Docs.