Facebook offers some real advantages for communities and community groups who want to enhance their communication.
It essentially enables groups with like minded interest to share information including general posts that everybody in the group can see plus their own information (photos, videos, details, etc).
There's a great article on the 9 steps Introduction to Facebook (see the link on the NSW Community Builders
homepage).
Also, if you have an interest in the application of Facebook for businesses, here's a blog post from my friend and colleague John Jantsch on the subject.