Want to know exactly how you are making use of the Firefox web browser?  Here are six of the best add-ons for Firefox that will give you every statistic you would ever want from your own day to day usage.  From cache, to download usage, and even easy cache status – we have something here for everybody to make use of.
Net Usage Item – Displays a progress bar of your Internet usage (grabbed from your ISP) on your Firefox [...]

Want a Firefox extension that helps you visualize your Internet usage? Look no further than the Net Usage Item extension. Here are a few more details about it.
The Net Usage Project is aimed at providing internet usage indicators for the Firefox browser. It works by fetching numbers from an XML feed or usage web page provided by the ISP. This project is targeted towards Australian Broadband Users whose broadband connections are encumbered with download (and sometimes upload) [...]