Quote Originally Posted by bossel
This can be easily done in FF as well. Just rightklick on a toolbar, click "customize" & drag&drop the icon to where you want it.
OK, got it now.

"Reveal More Tab/Window Options

There are some hidden options for the Tabbed Browsing that will allow you to force links that open new windows to open in the current or a new tab. First, add the following code to your user.js file:

// Reveal more tab/window options:
user_pref("browser.tabs.showSingleWindowModePrefs" , true);
Thanks ! I also found this here

First, it didn't work because they said to add the user.js in /profiles/, but in my FF version the directory is named /greprefs/

Oddly, it also didn't work by editing the about:config before I found about the /greprefs/

I now have a satisfactorily customised Firefox !