Markku Seguerra has come up with a possible alternative for Dave Shea’s comment highlighting which can easily be implemented with WordPress. This has been used successfully in a couple of sites, including Binary Bonsai.
A small description from Markku’s site:
Simply said, it allows you to highlight the significant and noteworthy comments posted on your WP blog. For my layout, I have the plugin configured to add a class=”noteworthy” to what I find fit.
You can download the plugin from here: