$(document).ready(function(){
    var current;
    var index = 0;
    var quotes = jQuery.makeArray($('.quote'));

   function rotateQuotes(){
      if(current)
        current.fadeOut('slow');

       current = $(quotes[index++]).fadeIn('slow');
       index = index % quotes.length;

       window.setTimeout(rotateQuotes, 5000);
   };

   rotateQuotes(); 
});