Man and I thought I was the only problem.
To be honest, people in the world are jerks. They're stupid, rude, ignorant and don't realize how hard you work on your site.
Carbondesigns.tk spammed the

out of my shoutbox. I saved the posts and posted a new article talking about it.
He has stopped now that he realized he was making a HUGE fool out of himself.
I guess the best thing is to delete them. Don't feel bad. I have to delete the occasional shout out on my shoutbox. It's a part of being a webmaster.
I'm almost positive there isn't a simple shoutbox out there that doesn't contain either: spam (advertising someone's site), profanity, or some rude nasty comment.
Just like it go. Delete the posts and move on. Not much you can do. If you post an article on it on the main page people will be motivated to do it even more. I've seen it.
It's okay Mog, don't worry.