I recently signed up at Likaholix - a new social network where you can share your likes with other members. This can be anything you have found on the internet - sites, products, books etc. If you have at least 10 likes in a particular category, you become what is called a Tastemaker, which gives more weight to your recommendations.
I've only just recently joined, but it seems like an interesting idea, and was set up by two ex-Google employees. At the moment, joining is by invitation only, so if you're interested I have some invitations (30, I think) if you click here.