Firefox 3 Tweak Guide

Firefox is very customizable, but not everybody knows how to tweak it. Koroush Ghazi has created a Firefox Tweak Guide to be used by everybody which can be downloaded and read. It consists of 13 cool chapters. It's a must-read article if you like to tweak your own Firefox. He used Firefox 3 as the basis of this article, so i guess it won't be much a problem, as most of you uses Firefox (i assume).