Bozo comments and such.

Using WP2.5 (and higher), is there a way (much like BBPress) where a commenter can block particular comments from their view? For example, let’s say that I don’t want to ban a certain user, but his comments are irritating another user to the point of no longer commenting.

In BBPress, users can be made “bozos”, which means that their comments are only visible to themselves.

I can’t seem to find anything like this for WordPress. Ideas?