You can mark every single forum as read, at the bottom of
http://www.daniweb.com/techtalkforums/index.php
You can mark an individual forum as read, at the top of
http://www.daniweb.com/techtalkforums/forum8.html
But there doesn't seem to be a quick way of marking a forum group as read.
http://www.daniweb.com/techtalkforums/forum2.html
:(