Why would you want to ignore someone exactly. Surely it would only be to admit defeat in a debate. If you truly feel that something someone posts is hurtful/slanderous/untrue, then it breaks the Rules of the site, and therefore, rather than ignore it you should report it.
If you only want to ignore someone, cause you don't want to read their posts, then deal with it and skip their posts.
I think most of us are only joking Neil. What good would reporting someone who breaks the rules do? It's usually the staff that are breaking the rules.