Share with Facebook is a small extension that adds Facebook Sharing in Safari 6. Once installed, it will display a button with the Facebook logo in the browser toolbar.

The Facebook sharing extension installed in Safari 6.

Tip: when you click the Facebook share button, a new page will appear, and will not close automatically when you press the “Share Link” button. You just need to press it once, and then close the page or hit the “Back” button.