I just installed a new feature to the forum, an Ignore button which appears with each post.
This is a feature that I wish I didn't have to install, but a lot of people have asked for this feature, so here it is.
The way it works is simple: If you don't want to see any posts from a particular person, just click the "Ignore" button located in the bottom-left corner of that person's post. From that point forward, you will not see any posts from that person. It can be undone by clicking "Unignore".
If you don't want to unignore that person, but still want to see a particular message posted by that person, you can click the "show" button (upper-right corner of the post) to unhide that one message.
From your profile settings, you will see a new "Ignore user options" link under Modify Profile. That screen will show you who you're ignoring,
and, more importantly, if you are being ignored by someone else. I would hope that no one gets ignored, but I think it will send a strong message to anyone who is.
EDIT: I changed the behavior so that you cannot actually see who is ignoring you. But, you can see a count of the number of people ignoring you from your profile summary page.