Opt out of certain forums?

[BrandiDup]

I know (or I'm fairly sure at least) this exists... I've seen it before. I am having a hard time locating it though.

I need a modification that will give users the option to "block" or "opt out" of certain forums so they won't show up in the "New Posts" search. It doesn't matter if they are still listed on the main forum page, as long as the posts don't come up within the new posts if they choose to opt out.

Thank you so much, in advance!