"Stumble Upon This Website" Button for Randomizing Posts in WordPress?

Is it possible to have a button that allows users to go through all the posts and pages in a WordPress website similar to how StumbleUpon works? Is it perhaps possible to do this with StumbleUpon somehow? I saw one website a while back that had this button in their sidebar but I can’t remember which one it was…

EDIT: Found it – http://www.filmschoolrejects.com/