Just read this: Discovering pages “similar to” ones that you like – from the Google Blog. From it:
One of the great things about the web is choice. There’s a website out there for nearly everything, and sometimes there are many sites all dedicated to a single topic. But how can you find all the sites that are related to the subject that interests you? This week, we launched a search feature that helps you easily find new websites that are similar to the ones with which you’re already familiar.
If only they’d add a “Like” button to Google’s results. Oh wait….they kinda have.
I do believe Google’s response to the wave that is Facebook’s Open Graph and Like is going to define the company for years to come. The game’s afoot in the search+social space.