Just for fun, take a look at the Bad Gimme Fade Demo to see what happens when you fail to properly manage the animations with GUIDs and the Gimme.Animation.end(..) function.
g(window).addEvent('load', init);
function init()
{
var nav = g('#navigation');
var buttons = nav.select('button');
var duration = 500;
nav.addEvent('mouseleave', function(e)
{
Gimme.Animation.end('FADEOUT');
buttons.fadeIn(duration, 'FADEALL');
});
buttons.addEvent('mouseover', function(e)
{
var link = this;
Gimme.Animation.end('FADEALL', 'FADEIN', 'FADEOUT');
g(link).fadeIn(duration, 'FADEIN');
nav.select('button').filter(function(el) { return el !== link; }).fadeTo(null, .4, duration, 'FADEOUT');
});
}