You can do that, or you can go to the Thread Tools tab. If you click on it, it will give you a drop down menu and you can click Subscribe to Thread.
Posting anything will subscribe you, IF you have it set up that way in your profile (I think its the default, though); but if you don't feel like posting, you can subscribe the other way w/o. (You can also UNsubscribe using the Thread Tools if you decide you no longer want to be notified of new posts in a particular thread.)
Hope this helps!