It'd be awesome if the forum software gave me the option to ignore both entire threads and individual users.
If I ignore a thread, I wouldn't want it to appear in the result set of "New Posts." That way I could more easily ignore all the incessant, yet utterly useless, chatter created by tugs of war, word association and any other thread designed to suck away time while offering no value to me. Or perhaps you could let me ignore the entire "Off Topic" forum. That'd be a 3rd option, as there are plenty of useless-to-me threads that don't live in the Off Topic forum.
Ignoring a user could be more challenging, since I'd end up seeing replies to the user's posts. But I'd probably get used to that. And I'm sure there are those out there whose first move would be to ignore me as well.
If I ignored a user, I wouldn't want them to be able to PM me either.

