Dumbledore's Army - join
"It is our choices, Harry, that show what we truly are, far more than our abilities" - Albus Dumbledore (Harry Potter and the Chamber of Secrets).
Low activity, 678 members

rec.arts.books.tolkien - join
The works of J.R.R. Tolkien.
Low activity, 486 subscribers, Usenet

Harry Potter Lexicon - join
Harry Potter Fans Group
Low activity, 227 members, moderated, restricted