A lot has happened in the field of share buttons in the past year: Google +1 button for web pages was introduced, Facebook started to migrate the Share and Like buttons, TweetMeme button is slowly getting replaced by the offical Tweet button, etc. Enough to make maintenance of these buttons a pain in the ass. But since social activity is getting more and more important for SEO, this needs to be done, one way or another. To make it easier, I've put together a comprehensive list of different share widgets, together with some explanation, sample code and direct links to full documentation.