I'd love the HN community to review this product. We are ex-Google News, Microsoft Research, thats trying to build the ultimate discovery product for your browser.
Pugmarks is social search too. It indexes documents going through your social circles and makes it available in the right context.
Pugmarks works great on LinkedIn profiles - giving you news and articles about a person, or interesting to the person.
Pugmarks extracts themes to your browsing, and makes your New Tab a mirror of the ideas going through your mind.