Yesterday I posted a GreaseMonkey script to hide negative users. After poking around, I found out that Chrome extensions were a much better way to go.
It's not pretty, but if you download the file, click it to install, and add some folks to the block list, they will be conveniently hidden from your view.
Notes: Only enter the portion of the user's name that is displayed, including any "..." if it's abbreviated. Usernames are grabbed straight from the displayed page. Also, clicking "Clear Blocked" will remove all entries.
You have a checkbox to hide all negative posters if you'd like as well.
Like I said, it's incredibly raw. Suggestions welcome.
Edit: It's hosted with all the real Google Chrome Extensions now...
Another edit: Cleaned up the look a little bit, made it more MGoBloggy. Also added an option for indicating where a post has been hidden with a red box. Especially nice so that you don't think someone is cussing out an innocent bystander.