Here is some javascript to help follow LW comments. It only works if your browser supports offline storage. You can check that here.

To use it, follow the pastebin link, select all that text and make a bookmark out of it. Then, when reading a LW page, just click the bookmark. Unread comments will be highlighted, and you can jump to next unread comment by clicking on that new thing in the top left corner. The script looks up every (new) comment on the page and stores its ID in the local database.

Edit: to be more specific, all comments are marked as read as soon as the script is run. I could come up with a version that only marks them as read once you click that thing in upper left corner. Let me know if you're using it or if you'd like anything changed/added.