First of all, hardly any root-node remains without replies for more than an hour. As for the OP being able to 'raise a flag', I don't see much benefit from that. Most of the time, the OP will not be satisfied because he doesn't recognize a good answer. Either because there are conflicting answers, or no good answers at all, or because of lack of understanding. Or because he asked the wrong question. Setting a flag doesn't solve this problem. Further asking may.
in reply to How do you find nodes that need your answer most?