If you want to discuss a certain question that has been posted on Web Applications, you can create a room for it.
To do so, just prepend "chat." to the question link. For example, if you want to chat about https://serverfault.com/questions/145777, visit http://chat.serverfault.com/questions/145777. If there is an existing room for this question, you will enter it immediately. Otherwise, a new room will be created with you as the owner.
I found two issues on this topic: