crimson If you look on a posting, say mine here to the right it say's private message for that person and if you click it allows you to send a message.
I find it a bit frustrating as there seems to be no way of knowing if you have a personal message other than receiving an email to your personal email you signed up with, and sometimes it is ages later when i get to check my emails, so you loose some of the benefits of instant talk.
I think we should have some form of instant chat on here.
I hope that helps, and I am not talking out of my head.