Customizable and nice.
I was only missing the possibility to make it remember that someone already clicked on that sign, to make it go away forever - so I added it myself.
add
if(isset($_COOKIE["geomessage_seen"])) die();
to the top of tools/notifys.php

and

,callback : {
afterClose: function()
{
var expires = new Date();
expires.setTime(expires.getTime() + (1 * 24 * 60 * 60 * 1000));
document.cookie = 'geomessage_seen=1;path=/;expires=' + expires.toUTCString();
}
}

to the end of the JS call (about line 93). cheap and simple. ;)