Plaxo .. the social

Got confused in number of social sites,Plaxo can help.
Its somewhat an online address book,which automatically updates contact's information.
User has to provide his and his Friend's' contact to Plaxo ,so when information is changed by a user, the changes appear in the address books of all those who listed the account changer in their own books.
Means you can get updates of what your feiends are doing on other social sites as Flickr,Picassa,Bebo,Facebook,digg etc.
It also has a calendar facility which syncs with Yahoo!, Gmail, and Outlook .
Its desktop app ,Notifier,is too a cool one it alerts you when your friends share videos, messages, and photos on Pulse and provides a quick access to Plaxo.com from the Windows system tray.
Above all it has a clean and neat user interface.