Creating a Scrolling Back to Top Button with jQuery
From the blog:
If you take a look way, way, way down at the bottom of this page, you will see a Back to Top button that scrolls the whole page until it reaches to top. It is a pretty simple effect to add to your site and looks a hundred-times cooler than just using your typical anchor name and link. Getting it all to work takes nothing more than a few lines of jQuery version 1.4.2.