Source: http://lifehacker.com/5576500/chattertree-is-a-private-facebook+like-social-network-for-families
If you love the idea of using social networking to unite your far flung relatives but aren't too excited about using a wide-open network like Facebook, Chattertree offers private and feature-rich social networks for families.
You'll find all the things you expect from a larger, Facebook-like social networking tool in Chattertree. Messaging, birthday alerts, group chat, photo and video sharing, and more. You can create rooms for various family members to gather in—like a room for all the kids to chat in or a room for planning the next family reunion. Chattertree even supports multi-feed video chat so up to six families can video chat at one time.
If you're looking for a way to keep up to date with a big family without the openness of Facebook and the accompanying privacy issues, Chattertree is a solid solution. Chatterbox is a free service and requires a basic email registration for all participants. Have a preferred solution for setting up a private social network? We'd love to hear about it in the comments.