FreeGameDev

It would be nice if we could combine the various "feed.php" modes with a specific subforum, eg:

http://forum.freegamedev.net/feed.php?f=53&mode=topics - Show only "new topics" in the subforum "Red Eclipse"

Currently, you can only specify either a subforum, or a feed mode (so you can only get latest posts within a forum, or only new topics for the entire FGD forum).

I highly recommend to try using http://pipes.yahoo.com , as I believe that this would be easier and more reliable than modifying phpbb to have that feature.