There's a list of registered users that lurk but never post, and an even longer list of Guests. The number of people that post regularly isn't all that great, but I think participation encourages participation, so never shy away from adding your two cents.
I lurked for a while, then registered pretty much only to comment on stories, but eventually Toe & the Gang dragged me out of the basement, and it's a fun place once you get to know everyone a little better.