document.observe('dom:loaded',function(){
        var newsSource = $('yourListId');
        var delayBetweenItems = 3;
        var effectSpeed = 0.6;
        var tag = newsSource.firstDescendant().tagName.toLowerCase();
        var data = newsSource.select(tag).invoke('hide').pluck('innerHTML');
        var news = newsSource.down(tag).show();
        var index = 0;
        var newsCycle = function(){
                index = (++index >= data.length ? 0 : index)
                new Effect.Fade(news,{
                        delay:delayBetweenItems,
                        duration:effectSpeed,
                        afterFinish:function(){
                                new Effect.BlindDown(news,{
                                        duration:effectSpeed,
                                        beforeStart:function(){
                                                news.update(data[index]);
                                        },
                                        afterFinish:newsCycle
                                });
                        }
                });
        };
        newsCycle();

});