The location bar in Firefox is a pretty empty, so here's a great way to add functionality to it, making navigating the just a bit easier.
UrlbarExt adds seven buttons to the location bar giving you a range of useful functions. You can copy the URL, automatically create a shortened URL, search the site in Google, go up the site tree, navigate through sequential URLs, add tags to URLs and surf anonymously using online proxy servers (which you can choose from).
The tiny URL button is really useful for anyone who uses Twitter, because it saves space, and it's great to be able to do it in a single click. All UrlbarExt's other buttons work very well - the copy option is especially useful while browsing and writing, as it really makes it faster. There are very deep settings options, and some of them are a bit daunting for the uninitiated.
I had some trouble using the 'Anonymous Surfing' button, but it's definitely not the most important feature of this little add-on. It's probably not useful for casual users, but anyone who works with browsers a lot will find this a really great tool.
UrlbarExt is a fantastic little add on that can actually improve your productivity online.