What is the social bookmarking plugin called

I'm looking for the social media tabs/bookmarking plugin. You know the one with the "share this article" or twitter, facebook, delicious,digg and technorati etc, icons. That appears on each post.

I could have sworn I saw it when I first browsed thru the plugins list but now I can't find it anywhere. Or maybe I saw the code somewhere.
Anyway can someone point in the right direction.