A social cookbook based on Facebook's Open Graph:
https://developers.facebook.com/docs/beta/opengraph/.

You can see all the recipes in your friends' cookbooks in addition to your
own. When you add a recipe to your cookbook or cook a recipe, your friends
will see it in an activity feed on Social Cookbook as well as Facebook
via Open Graph.

You can play with the site at http://socialcookbook.me/

To run your own version of the site or locally, copy settings-template.py to
settings.py and edit all the options to your local setup. The Amazon S3 and 
CloudFront settings are required to support photo uploads for your recipes.
The rest of the options should be self-explanatory.