#preloadedImages {
       width: 0px;
       height: 0px;
       display: inline;
       background-image: url(path/to/image1.png);
       background-image: url(path/to/image2.png);
       background-image: url(path/to/image3.png);
       background-image: url(path/to/image4.png);
       background-image: url();
}

A low-tech but useful technique that uses only CSS.  After placing the css in your stylesheet, insert this just below the body tag of your page: "".  Whenever the images are referenced throughout your pages they will now be loaded from cache.

CSS Image Preloader

css, images, cache

CSS