The Unitarian Universalist Christian Fellowship now has a Facebook page.
It's a great idea to have a Facebook page or group for your affinity group or society - that way, members can link together; you can raise awareness of your group and the issues you care about.
I'm a member of the CUUPs group (Covenant of Unitarian Universalist Pagans) on Facebook, and it has some quite active discussion topics.
Because people see things in the Facebook feed, having a Facebook page boosts the numbers who are interested in your group - but only if you post things (comments and articles) regularly on your wall.
Find out more about Unitarian societies and UU societies.