Cookbooks is a project mainly written in Ruby, it's free.
chef cookbooks
Here's some cookbooks I've written for Opscode Chef. I'll try to keep them updated, but patches/suggestions are always welcome. Also it should be noted I'm a sysadmin not a true developer ;)
uses a databag similar to this for server configuration
$ knife data bag show my-awesome-company application { "repo": "git://git.hackerna.me/myapp.git", "id": "application", "revision": "HEAD", "deploy": false, "deploy_to": "/srv/myapp", "prod_role": "myapp-server" }