it's actually been requested before (http://shoutbox.menthix.net/showthread.php?tid=62977)
basically you could do it by replacing the avatar file in the place where msn stores them, and monitoring that file so that you replace it whenever msn does.
i'll see if i can hack together a really basic version of this.
![[Image: gybouserbar6hc.gif]](http://img181.imageshack.us/img181/7129/gybouserbar6hc.gif)
