Discover more than 20 behind-the-scenes tweaks for speeding up page loads, reducing memory drain and making the interface behave the way you want it to Ever since its debut,
Firefox has garnered a reputation for being an enormously customizable program, both through its add-on architecture and its internal settings. In fact, many of Firefox's settings aren't exposed through the Tools > Options menu; the only way to change them is to edit them manually. In this article, we'll explore some of the most useful Firefox settings that you can change on your own, and that aren't normally available through the program's graphical interface.
The closest analogy to how Firefox manages its internal settings is the Windows Registry. Each setting, or preference, is given a name and stored as a string (text), integer (number) or Boolean (true/false) value. However, Firefox doesn't keep its settings in the registry, but in a file called prefs.js. You can edit prefs.js directly, but it's often easier to change the settings through the browser window.
type
about:config in the address bar and press Enter, and you'll see all the settings currently enumerated in
prefs.js, listed in alphabetical order. To narrow down the hundreds of configuration preferences to just the few you need, type a search term into the
Filter: bar. (Click the Show All button or just clear the Filter: bar to get the full list back again.)
*very
LONG ARTICLE on tweaking the firefox, like 6 pages if your interested*
http://www.computerworld.com/action/article.do?command=viewArticleBasic&articleId=9020880