When we're designing and building a website or mobile application - for either the right or the wrong reasons - 'sharing functionality' has become almost obligatory.
People think that people want to like/share/tweet stuff. Anything and everything. Which is fine, and often they do.
So as a designer I'm always asked to incorporate these 'social' features. Finding myself continually in need of different variations of 'like', 'tweet', '+1' buttons and what not, I sensibly invested a little time consolidating these assets into a PSD.
The 'Social Media Sharing PSD'. Twitter, Facebook, Google+ and LinkedIn sharing components; all rebuilt as editable shapes/layers. Perfect for your mockups and compositions.
It might save you some time too. Grab it here. It's free!