gistfile1.js

site={
  config:{
    preloaded_images:['button_1_hover.png', 'button_2_hover.png', 'footer_link_hover.png'],
    images_rel_path:"/images/"
  },

  preload_images:function(){
    jQuery.each(site.config.preloaded_images, function(){
      jQuery("<img>").attr('src', site.config.images_rel_path + this);      
    });
  },
  init:function(){
    this.preload_images();
  }
};

$(document).ready(function(){
  site.init();
});