We're big fans of Backpack, the online PIM organizer with a pioneering KISS philosophy from the wildly successful 37signals. At times, however, Backpack can appear too simple, making it seem like the only way to interact with the service is through its pleasantly minimal web interface. Fortunately, this is entirely not so, and we just stumbled across two handy Firefox add-ons that bring quick navigation and easy clipping to this increasingly useful online info organizer.

First up is Backpack Pages, a simple toolbar button that acts as a simple drop-down bookmark menu for all your pages. As usually with any external Backpack tool, simply enter your username and private API key to get the ball rolling.

Second is a really useful add-on especially for users of Google Notebook or any other web clipping tool out there: Backpack Publish (pictured). Setup is again pretty standard, and now you can select text on any webpage and use this add-on's menu to create a List Item or Note to add to any of your pages without breaking your workflow.