I added a new link, "My Subscribed Threads", to the top navigation bar to make it easier to find threads you are subscribed to. By default when you create a new thread or add a post to an existing thread, you are automatically subscribed to it. When you click on the link, you will be taken to your UserCP where you will see all your subscribed threads. You can also access the list of subscribed threads when you are in the UserCP by clicking on "List Subscriptions"
You can also subscribe to a thread without posting in it if you want to keep track of it. Depending on the subscription option you choose, you can receive emails as soon as a new post is added to the thread or receive one email on a daily or weekly basis if a new post was added. To subscribe to a thread, go to the to the top of thread, click on "Thread Tools" and a click on "Subscribe to this Thread". You will then be taken to a page listing the subscription options.
I like that feature. Saves the step of subscribing to a thread to get notified when someone responds to the post.