I recently decided to open source this extension that I've been using personally for over a year. I use it heavily, but it especially comes in handy when I'm answering support emails for the product I develop, because it allows me to quickly pull up URLs (to documentation, support pages) to include in the support emails. The extension itself is extremely simple (less than 150 LOC), which makes it easy for others to visually check and audit:
https://github.com/binarynate/omnibookmarks/blob/74d140092a4...