On two other forums I frequent, they have a button/link that gives you a list of threads in which you posted and there are new replies. It's listed as either "Show new replies to your posts" or "Responses to my posts"

This makes my life much easier on the other forums, since I can quickly access threads to which I had enough interest in to post in, and not have to scan ALL the titles threadwise.

Seems this forum should have the same function, since "ALT+S" works.