Are you one of those people that likes to tweak around with what is behind the pretty Firefox curtain? If you want to jerk back the interface and get to the guts of the browser, you might need to jump here or jump there to get to the settings you need.
One person made this job a little easier with the Edit Config Files extension for Firefox. Once installed it gives you quick and easy access to such things as the about:config screen and your UserChrome.css file as well. Here is a full list of the options from the extension.
UserChrome.css, UserContent.css, prefs.js, user.js, Open Profile Folder, and about:config. Quick and easy access to all the tweakers’ tools. Now I wouldn’t suggest messing around with these unless you know what your doing – but if you do this extensions can be a real time saver because you no longer have to go on a hunt for how to open each of these options up.