Yesterday, Google launched Google Related, a browser add on that helps you find related content based on the page you are currently viewing.
Google explains:
When you're surfing with Related, you'll often see a thin bar along the bottom of your screen that offers videos, maps, reviews and other content that's relevant to that page. When you see an item you like, you can spread the word by using the built-in +1 button
Here is a video:
Gary Price has a great write up on it at Search Engine Land.
Chrome users can install the extension over here and it is now built into the latest Google Toolbar for IE.
Tedster at WebmasterWorld said, "Hmm.... sounds like it might be a way for websites to be sent MORE traffic through a Google product. Imagine that!"
Forum discussion at WebmasterWorld.