I usually use an adaptation of this, to take out the extra code that supports prototype and YUI (my choice is jQuery). This thing is super easy to use:
That's fine if you only need _trackPageview. The Google solution provides more capabilities though. Also, be careful of using 3rd party solution. They don't always work correctly. The jQuery plugin for GA used to cache-bust every request to ga.js, which definitely slows down your page.
I usually use an adaptation of this, to take out the extra code that supports prototype and YUI (my choice is jQuery). This thing is super easy to use:
jQuery(document).ready(function() { ga().config({ id:'UA-xxxxxxx-x' }).track(); });
It queues up any track calls and pushes them onto GA as soon as it loads.