window.addEvent('domready', function() {
    var list = $('showcase'),
        items = list.getElements('li'),
        length = items.length,
        max = length - 1,
        currentIndex = max;

    function rotate () {
        var next = items[currentIndex];
        list.grab(next, 'top');
        next.get('tween').set(1).start(1);

        currentIndex = (currentIndex + 1) % length; 
    }

    function move () {
        items[currentIndex].get('tween').start(0).chain(rotate);
    }

    items.set('tween', {property: 'opacity'});

    move.periodical(10000);
});