I don't know if this has been suggested yet. I did not see it.

An Ignore Poster list(kill file sort of thing). You could add names to your personal ignore list. In the Chat section, the links to posts by posters in your ignore list would be disabled, both in the main chat thread pages and the reply section of individual posts. I don't quite know how the Discuss section should handle it. Maybe have the thread show the post as **ignored**

It could help individual members control the board noise level to their taste without having to ask for a particular member to be booted.

Hombre: This is undoable as long as we use the Discus message board software. A change in software is not being considered anytime in the near future as of 2011