It would be utterly fantastic if the forums here included the ability to subscribe to threads, or otherwise be notified when a reply is posted in a thread you've contributed to. Call me lazy (though I prefer efficient), but I for one do not particularly enjoy maintaining a tab or bookmark, or running a search, just to see if anyone has posted a new reply. It's particularly annoying, and maybe even a little depressing, when you discover that no, no one has deigned to acknowledge your ramblings. To be melodramatic about it, it kind of makes one feel as though they're forever alone.
The idea was also suggested in a vaguely related thread (here) by Pascale and Zaeirra.