If you don't know about this, it's rather cool. Apparently, Google's archive of web pages is based on a technology called Alexa. One of its features is the ability to look at previous versions of the same page, known as the "wayback machine". You can even put a link on your toolbar to instantly see an entire list of all of the older versions of the page you were viewing. Interesting. And it even has a toolbar utility; drag this to your toolbar: Wayback