I have the beginnings of a recipe component at
http://www.princeclan.org/component/...ook/Itemid,77/
The front end is fairly complete. It is totally customizable via CSS.
Recipes may be added to multiple categories, and categories may be grouped to keep categories together.
User rights are fairly basic - a user is given add/edit rights, and this will allow a user to add new recipes and edit any recipes they've entered. It also allows entry of comments about any recipe. User rights may not be set by category. Edit: Also, anyone can view recipes, whether registered or not.
A mambo group level can be assigned as the minimum group level to allow admin access. Admins can edit any recipe or comment they wish.
Their is a search mambot to allow searching via mambo's search feature, and a module to list the most recent recipes.
The big catch: there's no back end, so user rights and categories have to be set up via PHPMyAdmin or something similar, and the component is not ready for multiple languages.
I'm planning on releasing it on MamboForge at some point. If you are comfortable maintaining the site via the database, I'd be glad to have it tested on another site.