Hi Terry
I'm not sure how your site looks, but most sites have external files. JavaScript may not be the case, but definitely CSS files? You can easily inspect the files that are being loaded (and their loading time) by using the Firebug extension for Firefox (http://getfirebug.com/). It's an extension every web-developer should have installed.
What I wrote and how you implement it has actually nothing to do with SilverStripe nor with PHP. Its a pure client-side issue (eg. what's running in the webbrowser. This is usually JavaScript embedded in HTML or sometimes flash).
This is how you could implement it using jQuery. The following code should be placed in the <head> of your template
<script src="jsparty/jquery/jquery-packed.js" type="text/javascript"></script>
<script src="mysite/javascript/sifr.js" type="text/javascript"></script>
<script type="text/javascript">
<!--
jQuery(document).ready(function(){
sIFR.setup();
});
-->
</script>
Using jQuery just for the DOM ready event is admittedly a bit overkill, but I'd give it a try just to see if it works. Another thing to try (without the use of jQuery) would be to place the following code just before the closing </body> tag!
<script type="text/javascript">
<!--
if(typeof sIFR == "function"){
sIFR.setup();
};
-->
</script>
The latter is probably better if you don't need jQuery for other stuff on your site.