I need to be able to add some data (text/images) to each comment in the comments section through a plugin. What I'm trying to do is actually very similar to the way the stack exchange sites have their little user profiles in questions/answers that show a user's points and badge count. I've tried using a few filters (most recently "comment_author" - yeah, didn't work too well) but haven't found something that would work. I need a spot where I can inject some information about the user that won't mess up other parts of the blog (like admin sections) and that will hopefully play nice with whatever theme they are using.
I realize starting out that this probably won't work for every theme but hopefully there is an answer for those themes that stick to the general blog layout.