I'm working on building a social networking site for homebrewers. Besides the stuff everywhere has (write, share recipes), I intend to add useful features like setting up trades of homebrew batches between members, a rating system, a way to print out bottle labels (with name, vitals, vintage, etc.). Also, publication of your recipes will be optional -- the site will have plenty of features for you to work in isolation, keeping track of your batches, and more advanced things like setting up reminders for how long you want a batch to be casked, etc.
I hope to also show (unobtrusive, text) ads for local homebrew shops in your area.
My question is, what other features would you guys really like to see in a homebrewing site? What things would be really helpful, for you the brewers, to help keep track of and manage your batches? Sharing and rating will be _one_ aspect of the site; I don't want to leave people who don't want to partake in that out in the cold.