Shoutbox

I suppose a script could play the sound file if you're set to busy...

js code:

---

function OnEvent_ChatWndReceiveMessage(ChatWnd, Origin, Message, MessageKind) // message received event
{
    if (Origin !== Messenger.MyName && Messenger.MyStatus === 4) // if you're busy and not the sender
    {
        MsgPlus.PlaySound("\\C:\\Program Files\\Windows Live\\Messenger\\type.wma"); // play the sound
    }
}

---