Just wanted to recommend a 'Dislike' button to be introduced alongside the existing 'Like' button for comments posted by users. Although I see some comments deserving of likes, there are other comments which deserve to be shown to be disliked by users. I've seen quite a few comments deserving of a 'dislike' over the years at HUKD and I'm sure others will agree. However, at present, there is no way to show that you dislike a comment besides commenting.
I've seen quite a few forums with both a 'Like' and 'Dislike' option and think it's a very good idea.
Personally, I think that those hitting the dislike button shouldn't have their name publicly displayed as it is with those that have 'Liked' a comment (which I also don't really like IMO).
Here's a couple of examples of forums adopting both the 'Like' and 'Dislike' button:
MacRumors - http://forums.macrumors.com/showthread.php?t=1324021
The Student Room - http://www.thestudentroom.co.uk (click on any random thread).
Anyways, that's my recommendation. Hope others agree.