jQuery.preloadImages = function(){
    for(var i = 0; i<arguments.length; i++){
        jQuery("<img>").attr("src", arguments[i]);
    }
};
// Usage
$.preloadImages("../img/zoom_kyushu.jpg", "../img/zoom_okinawa.jpg", "../img/zoom_chugoku.jpg", "../img/zoom_shikoku.jpg", "../img/zoom_hokuriku.jpg", "../img/zoom_kansai.jpg", "../img/zoom_hokkaido.jpg", "../img/zoom_kantou.jpg", "../img/zoom_tohoku.jpg", "../img/zoom_s_fukuoka.jpg", "../img/zoom_s_okinawa.jpg", "../img/zoom_s_osaka.jpg", "../img/zoom_s_sapporo.jpg");