Yep, I use Firefox and a variety of add-ons. If you haven't explored
the list, you really should. There's something there for everyone.
Here's what I have installed.
Adblock - usually turned off, though.
ColorZilla - shows you the color under your mouse pointer (useful for web design)
LiveHTTPHeaders - allows you to see and modify raw HTTP requests
ReloadEvery - reloads pages every X seconds
SplitBrowser - allows you to split the browser window (either the same page or open an alternate page in a split window)
Text Link - double click on a plain text link to open it in a new tab
User Agent Switcher - switch identity of the browser (make it appear as Internet Explorer, Netscape, etc.)
Viamatic foXpose - shows thumbnails of all tabs on one screen (slow, I rarely use it)
Just for reference, I used SplitBrowser to open a split screen with Google to search for all of the links to those extensions. So rather than two windows open so I can edit my post and view the results on the same screen, I just split the existing browser window. Probably not useful all of the time, but can be handy every now and then.
---John Holmes...