I’ll probably come back and update this post, but I wanted to post some excellent addons or tools that can be used with Firefox/Firebug, available here:

10 Firefox Add-Ons for Web Designers: http://www.10voltmedia.com/blog/2009/05/10-firefox-add-ons-for-web-designers/

10 Firefox Extensions for Web Analytics: http://www.thomsonchemmanoor.com/10-firefox-extensions-for-web-analytics.html

FireAtlas, an ASP.NET AJAX utility: http://fireatlas.chesnaistechnologies.com/