I'm one of those many people that procrastinate-by reading Hacker News. So in a helpless attempt to be efficient I've created hnCommentWatcher. Yet another HN bookmarklet. Currently I swear by @mrspeaker's Hackemup bookmarklet, it really is brilliant, but its only for the front page, and I still find it painful to follow the comment threads for each individual post (which I believe is where I get the most use (see: intellectual stimulation) out of Hacker News). So this is my solution.
What it does:
hnCommentWatcher is a bookmarklet that you use on individual posts/threads, which then refreshes the page every so often and indicates which comments are new, and allows you to easily navigate between them, meaning you can open a thread read the comments then come back later and follow the discussion without having to decifer which comments are new and which you've already read.
How to use it:
Read the instructions on this projects homepage: http://christopherdebeer.github.com/hnCommentWatcher/
This is a work in progress I just made it, so it might be a bit buggy in some browsers that I havnt tested yet. Also this page could do with a few proof reads. If you have any feedback or bug reports, please post them to the issues page of this projects github repo.