Chronicles Network – Science fiction and fantasy forums, covering literature, films, TV and writing.
Ex Isle – A messageboard for friendly science fiction enthusiasts.
The Guild of Fantasy Writers – Bulletin board-based chat for fantasy and SF writers, poets and artists. Works can be posted and critiqued by other members.
Science Fiction Readers – For fans interested in reading and writing science fiction. Community site with forums, reviews and wikis.
SciFi Forums – Online community with its focus on the media and TV side of SFF.
SciFi.com: BBoard – Chat based about SFF genre TV, movie and book topics.
SF Announcements – Bulletin board for posting news and announcements related to SFF.
SFcrowsnest.com: Communities – Bulletin boards on topics such as author JG Ballard and the TV series Doctor Who.
SFF Net – Online community of genre authors, publishers, editors, and readers. Includes the chat system for the Science Fiction and Fantasy Writers of America.
SFsignal – Science fiction and fantasy blog including news, reviews and points of view.
UK Fantasy Database – SFF books with information on authors, reviews and a forum to ask questions
Upon-a-Dream – Bulletin board for SFF genre young adult fiction.