I'm not even sure if this was suggested or not but how bout adding little like 'checks' or green dots by people's icons to show if they were online? It could be toggable y'know for people to be lurkers. Also how bout something like a 'top commentor/contributor' status for some people. Unless that would be too 'status-y'..I saw on some sites that you could rate comments with up or downs but that could be a cause for drama...nevermind.
I agree with Frosted Mini Wheats, we really should bring back COTW in some form or another.