Still using Firefox ? Here is a good list of firefox add-on http://anidandesign.com/web-design/my-favorite-firefox-add-ons/
firefox
Tool to SpeedUp your website
Introduction YSlow is a FREE tool analyzes web pages and tells you why they’re slow based on the rules for high performance web sites. YSlow is a Firefox add-on integrated with the popular Firebug web development tool. YSlow gives you: Performance report card HTTP/HTML summary List of components in the page Tools including JSLint How…