(function($) {
  var cache = [];
  // Arguments are image paths relative to the current page.
  $.preloadImages = function(images) {
    var images_len = images.length;
    for (var i = images_len; i--;) {
      var cacheImage = document.createElement('img');
      cacheImage.src = images[i];
      cache.push(cacheImage);
    }    
  }
})(jQuery);