Forum Response Messages

We all know that you get messages when someone responds to a forum you started, but wouldn't it be nice to get messages when someone responds to a forum you've responded to? I tend to post in someone else's forum, then totally forget that I posted there until I wander back a month or two later. By then, I've missed any responses to my post!

I think this would be best implemented as a check-box option - when you're looking at a particular forum post, there could be a box in one corner that says "Subscribe to this topic?". Once you subscribe to a topic, the text could change and read "Unsubscribe from this topic?"

Thoughts?