Youtube          : www.youtube.com/
Twitter            : http://www.twitter.com/
     Wallwisher      : http://www.wallwisher.com/
     Facebook       : www.facebook.com/
     Windows Live: http://www.windowslive.com/
     wikipedia        : http://www.wikipedia.org/
     Google App   :  http://www.google.com/apps/ 


My Favourite application is facebook as you can chat with friends, watch videos and post thoughts so it is like an all in one application.