I've only found four, I think I might not have been on the site long enough, and not frequent enough of the subforums, to get the clues immediately. So I'm browsing the subforums now to see if anything makes me think of a clue. I'm working in reverse, but I guess that's a valid method if you're not finding eggs where you'd think you would!
I think I'll be doing random thread checks when all clues have been added.