thargas,
Perhaps you missed where the CGI checks how long it has been since a request was made? That will be for all clients. The trouble I see with it is a race condition where two clients check at the same time and both think it is ok. One actually gets delivered and the other gets queued with no notice to the user. I am sure that since we are doing whiz bang AJAX that we could tell the user the approximate wait time even after they are in the queue though.