I suggest a bookmarking mechanism for forum posts.
I often read a post and I know I have something to say but it needs some more work to be done and I do not have the time while I'm reading that. At the moment it's hard to come back to that respective thread. So, I would find a bookmarking mechanism handy, ideally with the ability to add a short comment. That would prevent forgetting about the post.
Subscription to notifies is not a real good alternative, because one gets lost over the pure amount of subscriptions. Also, the bookmark can be deleted when it's not needed anymore, whereas one usually wants to follow the discussion.