Cimorene

Actually, that's another thing. You don't actually join anything, nothing's expected of you, and you aren't expected to do anything or interact with anyone else. It's almost an anti-club.

I am happy, for example, to put a little Dragnet fanlisting icon on my Dragnet icon page. Even something as uninvolving as lurking on a Dragnet mailing list, assuming any exist, would be a different proposition. ;)