CommentsRSS create an RSS feed of all discussions AND comments together in one feed (comment subject lines are identified with "RE:..."), with feeds available for all posts and by category.
The feed for all posts is available at...
And for individual categories...
Remember that your forum URLs may use index.php, in which case they may look like this:
CommentsRSS is an adaptation of Tim's old AnnouncementsRSS plugin.
Thanks to Tiling Forum for sponsoring this plugin.