I've added the code that I've previously tried. Lets see if it works.
To ignore somebody, click the red 'I' in the persons mini-profile. To unignore them, click the red 'U'.
Here is what the author of the code says:
This code will put a button in each user's profile, that, when clicked, will cause you to ignore that user's post/pm/calendar entry. If you are ignoring someone, anoter button is put in their mini-profile which, when clicked, unignores them.
. All ignore info is stored in the cookie so if you delete your cookies or use a different computer, your ignore list will not be available