The Firefox Add-ons industry is extremely interesting and great stuff like the Scribefire Blogger Add-on have been downloaded more than 1 Million times.
For Web Analysts, there are 10 interesting plugins:
1. Web Analytics Solution Finder (WASP)
I forgot who made it, but somehow Stephane Hamel comes to my mind. I might be wrong, but definitely interesting
2. Data Analytics Firefox Add-on
Allows to play around with data
3. TrackMe Analytics
Never tested, but sounds good.
Well...we've seen it before and 12 Million downloads speak for themselves
5. Google Analytics checker
For the people who do or don't like the Google borg collecting data
Like WASP. Have never used it.
Let's you view GA in your browser. Never played with this either.
8. Better GA
Supposely let's you surf invisible. Well...why not.
10 Alexa Sparky
I really like this tool, b/c it displays Alexa ranks in the bottom right instead of in the middle of the site. I use it all the time.
If you want to get all the links, images and better explanation, head over to Thomson's blog.