Today I noticed that the social network buttons on my blog had disappeared - I quickly realized that this was because I had recently reset my theme. Of course, I had to bring those buttons back, but better. By chance, I stumbled over the socialshareprivacy projectcache (sorry, german only. project site with downloadscache) of german news site and publisher heise.
It's really simple: We have an ulist of our buttons. At the beginnig, we just show a greyed out image for each one. If you click it, it's replaced by the real button. I've also added HackerNews and Reddit buttons - the original only contains Facebook, Google+ and Twitter. Hope you like it :)