I've tried a few Safari extensions for adding pinboard.in bookmarks, but this is the best (apart from the dedicated Delibar extension).

Simple but effective Safari Extension to send the current page to the Delibar app.

If you're a Firefox or Chrome user, this is an amazing extension to bring a LaunchBar/Quicksilver type of interface to web browsing, adding some very useful commands along the way.

If you use Firefox, this saves having a collection of other bookmarklets or toolbar buttons for a variety of services.

A very interesting and accessible-looking project, showing once again how brilliant jQuery is.

Useful-looking development documentation sidebar for Firefox. Works for a number of languages.