It's the 66,666th post of all the posts currently on the forums. That number is incremented every time a post is made, but of course, some posts are deleted, and other posts don't count towards the post count (i.e. Staff room).
So if you want to go by actual appearing posts, it's mine. If you want to go by the id of the post, it's this one: http://atheistforums.org/post-66666.html#pid66666
So if you want to go by actual appearing posts, it's mine. If you want to go by the id of the post, it's this one: http://atheistforums.org/post-66666.html#pid66666
