The folks at Sphere just created a customized Sphere Contextual Widget for my site. This tool allows readers to click on the “Sphere It” link at the bottom of any post and get a pop-up of contextually related content from around the web. I’ve also added some links to blogs that I think you will like if you like this one.
What is Sphere?
From the Sphere site– “We bring you the good stuff  a very simple idea that takes some smarts to do right. Sphere’s advanced search algorithm helps you discover high-quality, relevant, and timely blog posts and makes it possible for publishers to integrate contextually relevant blog posts alongside their articles.”
Sphere also recently created a WordPress Plugin so I’m guessing you’re going to be seeing alot of this tool.