jquery.ticker.js

(function($) {
	var defaultOptions = {
		speed: 0.15
	};

	$.fn.ticker = function(options) {
		options = $.extend(defaultOptions, options);
		return this.each(function() {
			var ul = $(this);
			var container_width = ul.parent().width();

			var width = 0;
			$('li', this).each(function() {
				width += $(this).width();
			});
			width += container_width;
			ul.css({
				width     : width,
				marginLeft: container_width
			});
			(function loop() {
				ul.animate(
					{ marginLeft: width * -1 },
					width / options.speed,
					'linear',
					function() {
						ul.css('margin-left', container_width);
						loop();
					}
				);
			})();
		});
	};
})(jQuery);