Ever noticed how fast images load when paging through a Facebook photo album? This is because Facebook is preloading each of these images into your browser’s cache before you even view them. Here’s how you can achieve a similar behavior on your website using some jQuery magic. - http://www.nealgrosskopf.com/tech/thread.php?pid=77

image_preloader

var nextimage = "/images/some-image.jpg";
$(document).ready(function(){
  window.setTimeout(function(){
    var img = $("<img>").attr("src", nextimage).load(function(){
      //all done
    });
  }, 100);
});