Oinam Forum

Most of Add-ons that worked on the older version of Firefox will work in the new version of Firefox. If you're still using Internet Explorer, well you're missing the good part of an Online Life.

Firefox 3.x

iMacros
Search Status
FireBug
YSlow

Firefox 2.x
Firefox 2.0 Official Recommendations
GreaseMonkey
Customize Google
Download Statusbar
URL Fixer
Tab Mix Plus
Screengrab
Digg Button
Speed Dial
Compete Toolbar
Amazon S3 Firefox Organizer(S3Fox)
OneClick Installer for Wordpress
Social Media for Firefox Extension
Auto Shutdown after Download completes
BlueOrganizer

Firefox 1.x

DOM Inspector
ScreenGrab
ForecastFox
PDF Downloads
Web Developer
Download Tweak Manager
IE Tab
Del.icio.us
Session Saver
About Site
Blogger Web Comments
Lorem Ipsum Generator
Secure Password Generator
LiveHTTPHeaders
FasterFox
Google Bookmarks Button
Google Pagerank
Google Calendar Notifier
Gmail Manager
Tab X
Duplicate Tab
Google Browser Sync
Compact Library Extension Organizer
Firefox Extension Backup Extension
Swam the Dot
SEO for Firefox
Video Downloader
Sage - RSS Feed Reader
Performancing
All Peers
Nightly Tester Tools - A addon to make all old extensions compatible with new firefox build
Search Status
Firefox Flash Player Plugin Switcher
PermaTabs

If you are looking for more Firefox Extensions, follow the following links

Mozilla Extensions
50 Best Firefox Extensions for Power Surfing
Clav
Useful Firefox Security Extensions
Mozilla Firefox - Have It Your Way!
13 Great Firefox Extensions for Web Professionals