After testing LOTS of WordPress social sharing plugins, I've settled on this one.
Looks very nifty. The "printer-friendly version" button is an added bonus. As is the way it adds "you may also like" links and pics at the end of the article.
Has many options. You do NOT need to use them all.
You can re-arrange the share buttons by dragging them within the Shareaholic Dashboard.
You don't need an API key to share to Facebokok.