Pearltrees is an interesting concept. You collect the "pearls" of information that you value on the web and connect them in subject categories like the branches of a tree. Together all the branches of "pearls" represent your range on interests.
You can also drag in other peoples branches - and hence benefit from their collected pearls of wisdom.
This could be a very interesting Social Media Marketing Platform - yet, I found the usability of the site awful - not intuitive in the slightest. Also very slow.
However, the platform is in Beta though and thus maybe this is something to keep an eye on for the future.
