This is a cool little extention. You set up an account (for free of course) and install the extention, and you get a little toolbar. When you set up the account, you check off subjects that you're interested in from a fairly lengthy list, and then you click a button in the tool bar and it sends you to a random webpage from one of the subjects you chose.
This thing is great for when you're bored.
Check it: http://www.stumbleupon.com/