There's also the "Turn notifications on when you post or reply to a topic." setting in the Notifications and Email subsection of your profile. The forums have a email notification feature; it can be enabled for any individual thread by clicking the "Notify" link at the top right or the top left of any forum thread, and the exact mechanics of notifications can be tweaked through various profile settings. Enabling the setting I described would automatically enable notifications for any thread you create or post in from that point on. This is spammier than what most members would want, but it sounds like it might be exactly what you're looking for.
(*edit*) The Info theme Loc brought up adds some extra statistics and links to the standard UI, and it also presents a timestamp on every page load. Some members prefer that theme for those reasons. It also appears to provide an interface to some functionality that isn't presented anywhere in the standard forum theme. I think both the "Show new replies to your posts." and "Mark ALL messages as read" features are like this; I wasn't aware of either of those features until just now, and I don't think they're available through the interface of the standard theme. The "Show unread posts since last visit." and "Show Own Posts" features are accessible through the standard theme through the bottom of the main page and your own profile, respectively.
If you find that you like the "Show new replies to your posts." feature but dislike the rest of the theme, you can just bookmark the URL of that link
, and you'll be able to access that feature from the standard theme, even though the standard theme doesn't provide a link to that feature.