I use these Firefox extensions.
Install mozgest by Optimoz, the Mouse Gestures extension. This feature is less subtle than the word "gesture" suggests — it's more like semaphore — but the shorter gestures at least are useful. I use the history forward and backward gestures all the time, as it's much quicker than the Fittsian detour to the toolbar.
Install Tab Mix. I'm watching this one, but I still prefer Piro's Tabbrowser Extensions.
If you want more features than Tab Mix, install Piro's Tabbrowser Extensions. This is also called the Tabbed Browsing Extension. It's "strongly unrecommended" by Piro himself. He recommends Tab Mix.
I recommend these settings.
To show a bookmark's properties, right-click it and click "properties" at the bottom of the context menu. There's a bug: sometimes this won't work on a toolbar or menu, and you'll have to find the bookmark in the bookmark manager.
The "Location" property may contain the parameter (or formal argument) %s, which is used with keywords.
The "Keyword" property is a word that can be used in the address field to stand for the bookmark.
