Memory issue - http://tech.cybernetnews.com/2006/04/04/reducing-your-memory-usage-in-firefox/

Editing css tutorial - http://www.oreilly.com/catalog/firefoxhks/chapter/hack44.pdf 

A nice set of firefox plugin (user) - http://www.mozillazine.org/talkback.html?article=7976 
A nice set of firefox pluing (web development) - http://www.seo-expert-blog.com/blog/my-favorite-firefox-extensions http://www.dave-woods.co.uk/?p=139

Fizzer, a hacker tool - http://www.google.com/search?hl=en&client=opera&rls=en&hs=DRJ&q=mozilla+fuzzers&btnG=Search

Weave, introduce kind of proxy server for indiviual - http://labs.mozilla.com/2007/12/introducing-weave/

Disable endless "Authentication Required" popup - http://forums.mozillazine.org/viewtopic.php?f=38&t=1195105&p=6243155&hilit=authentication+required#p6243155

http://www.testinggeek.com/index.php/testing-articles/176-twenty-essential-firefox-addons-for-testing

Look like this one working, but pipeline is not good for my machine - http://webanthology.net/all-you-need-to-optimize-firefox-for-better-performance-33-tips/2009/11/29/