The Society for Creative Anachronism now has an official presence on Facebook. Maintained by the Social Media Director, the website includes a variety of links and contributed content of interest to SCA members.
From the About page:
The SCA is an international organization dedicated to researching and re-creating the arts and skills of pre-17th-century Europe. Our "Known World" consists of 19 kingdoms, with over 30,000 members residing in countries around the world. Members, dressed in clothing of the Middle Ages and Renaissance, attend events which feature tournaments, royal courts, feasts, dancing, various classes & workshops, and more.