$('.rotating-banner-item:first').show();

var timer = setInterval(fadeNext, 4000);

function fadeNext() {
	var current = $('.rotating-banner-item:visible');
	if (current.is(':last-child')) {
		var next = $('.rotating-banner-item:first-child');
	} else {
		var next = current.next();
	}
	current.fadeOut('slow');
	next.fadeIn('slow') 
}