This is one to watch. E is a new mobile social contact system that allows you to add a fellow e member to multiple social networks at once (twitter, delicious, last.fm, myspace, etc, etc) just by adding them as your e contact. Also they have a crazy gesture based device called the Connector that allows to E users to just swipe the devices next to each other to exachange contact info. Very futurist and really worth reading about.