phonescoop.com
i dont know why i didnt think of this before
i suggest there be a fourth, unsuscribe to read replys.
because, once you have read something, you dont really need to keep it in your subscriptions.
There's already a "Status" column that shows if there are new replies, and if you have read them.
The thing is, there could be new replies at any time. Of course a thread could have new messages posted at any time, but even for a message subscription, if you post, then someone replies, you read it, someone could still post a second reply to your original message. If you unsubscribed after you read the first one, you wouldn't be notified about that second reply.