Pinax is a Django project intended to provide a starting point for websites. By integrating numerous reusable Django apps to take care of the things that many sites have in common, it lets you focus on what makes your site different.
This site is a complete running example of Pinax with most of the features included.
For more information about Pinax, see http://pinaxproject.com/.
You can Sign up and Log in to try out the site.
At this stage, there is openid support, email verification, password management, site announcements, user-to-user messaging, friend invitation (both internal and external to the site), a basic twitter clone, interest groups (called tribes), projects with basic task and issue management, threaded discussions, wikis, blogging, bookmarks, contact import (from vCard, Google or Yahoo), photo management and a notification framework.