Editing a forum?

Hi all,
I was wondering if there's a way to change the way I see forums through Mozilla? Basically, a forum I participate in has a lot of flaming, and would it be possible to replace certain user's posts with emoted hearts and smily faces? I know this would only work on my computer, I'm not trying to hack the forum, just make it more enjoyable for me. It could access the xml data maybe? so that it knows when a certain poster sends information? I could use an apple script, but am open to other scripts. Thoughts on this? Also, it seems like someone probably already thought of something like this.

 

OHH! thanks you Chaos. I've used this before, just forgot about it.