which ur favourite add on ?

Firebug - helps in XHTML/CSS/JS development

Download Helper is my favorite firefox addon.I used it very frequently to download the videos from youtube.It's really helpful.Earlier we had to copy the link and paste it another site and wait for it to download.Now this plugin saves the video from the buffer once the video finishes loading. Another plugin which I used is the FoxTab which provides Aero like effect which we get in Vista.It really looks nice.

i use download helper to download videos from youtube and stuffs..

my favorite add on is web developer. it has various web developer tools. i think many web developer use this tool to support their work.