Control all Firefox add-ons, plugins and themes with Extensor

" ... Extensor is a powerful extension for Firefox that gives you better control of all installed add-ons, themes, plugins and even dictionary files and services."You can use it to change the state quickly which is great if you require some features only at times and not all the time. It is also great for quickly switching themes for example. ... "

Source: gHacks Tech News
Review  Control all Firefox add-ons, plugins and themes with Extensor