defer.js

(function () {

  var scripts = document.getElementsByTagName("script");
  var me = scripts.item(scripts.length - 1);

  function evaluate() {
    var script = document.createElement("script");
    script.type = me.type;
    script.appendChild(document.createTextNode(me.textContent));
    document.body.appendChild(script);
    document.body.removeChild(script);
  }

  if (document.readyState == "complete")
    evaluate();
  else
    window.addEventListener("DOMContentLoaded", evaluate, false);

})();