Pinboard Safari Extension
Super simple Safari extension for bookmarking the current page in Pinboard. Click the button and done.
pinboard.safariextz. Existing tabs need to be reloaded before using the extension.
Note: With the changes to extensions in Safari 9 on El Capitan, Safari might complain when trying to install this. It will probably be fine though.
Click the button to open Pinboard's default add bookmark page. The current selection is set to the bookmark's description (optional).