Making th message window automatically closing itself

Hi all,

I'd like to share an idea with you; tell me what you think about it.

I use IM a lot, like any of you. And when someone talks to me, I click
on the blinking icon in my notification area in order to make the
message window visible, which is fine. But once the conversation is done
I don't want the window to stay on the desktop because it's useless;
indeed, my only "entry point" in a conversation is done via the
notification area. 
And because windows in the windows list often change position (due to
new programs/windows opened), tracking the message window is such a
pain, and it is kind of duplicate since there is the notification icon.

So, to keep the long story short, here is what I propose :
1) The only way to get notified from a new message is done via the
notification icon; no blinking message window in the "list of windows"
anymore since it duplicate the "entry point". So if a message window is
already opened and there is an incoming message, just make the
notification icon blink - no need to search for the
always-changing-place-message-window.

2) If a message window stays more than x seconds/minutes[1]  without any
activity[2], it should be automatically closed so the user shouldn't
always click on the "close" button of it.

Any constructive comments are welcome ;)

[1] depending on user's preferences - a gconf key with a respectable
default : 30 seconds for example
[2] no incoming message, no message sent or being typed

Regards.