Lazy loading the addthis script? (or lazy loading external js content dependent on already fired events)

The simplest solution is to set parameter domready to 1 when embedding addthis script into your page. Here is an example:

<script type="text/javascript" 
src="http://s7.addthis.com/js/250/addthis_widget.js#username=addthis&domready=1">
</script>

I have tested it on IE, Firefox, Chrome, and Safari, and all worked fine. More information on addthis configuration parameters is available here.

This code solves the problem and saves the loading time that I was looking for.

After reading this post about how most current js libraries implement tests for a dom loaded event. I spent some time with the obfuscated code, and I was able to determine that addthis uses a combination of the mentioned doscroll method, timers, and the DOMContentLoaded event for various browsers. Since only those browsers dependent on the DOMContentloaded event would need the following code anyway:

if( document.createEvent ) {
 var evt = document.createEvent("MutationEvents"); 
 evt.initMutationEvent("DOMContentLoaded", true, true, document, "", "", "", 0); 
 document.dispatchEvent(evt);
}

and the rest depend on timers testing for existence of certain properties, I only had to accommodate this one case to be able to lazy load this external JS content rather than using the static script tags, thus saving the time that I was hoping for. :)