Mozilla about:config

Need to edit your Mozilla browser preference settings? Try entering about:config in the location bar. You'll find settings that you didn't even know exists.

It's not flash, but it gets the job done. Saves you having to hunt through numerous screens, especially if you know what you're looking for.

For a reference of what the settings are, please visit:
MozillaZine About:config entries

It is by no means a complete reference but it is a good place to start.