It would be interesting to see the number of currently active users at the top of the page. Maybe even have sub-counts per comment thread.
For example: you are at the front page. You see "521 active users". You click on the "comments" link of a story. You see "103 users viewing".
What do you think?
lobste.rs does this rather simply by gradually changing the background color of the logo depending on traffic.<p>It would probably be relatively easily to implement a similar feature here on HN, but would it be worth it?