Rethink Church is a project done by the United Methodist Church. It was built using Drupal, and various modules to allow users to come and share their thoughts on events, topics, and important matters through the site's conversation system. It also allows the team at UMC to be able to reach out to those that come to the site.
This site is at its core a very large blog site, allowing the Chruch to blog and post updates to various outreach missions and events around the glob. This is in order to get visitors to participate.
URL:
http://rethinkchurch.org