"While you can make privacy related configuration changes in the Firefox options, many advanced options become only available when you load about:config or install add-ons that provide you with frontend access to those settings.
"You can check out our list of best privacy add-ons for Firefox which gives you an overview of good extensions for that purpose.
"Tinfoil is a brand new extension for Firefox that makes quite a few privacy related preferences available in its options. ... "
Source: gHacks Tech News
More Tinfoil for Firefox provides easy access to advanced privacy preferences