Extensions
Open Selected Links In Tabs. I cannot live without this extension.
Open ED2k links properly
Group tabs from the same website together
Open This Image In PaintShop Pro
Reload this tab every $foo seconds.
Artificially extend the life of your session cookies
Because it’s Greasemonkey
Validation Is Good
Stops binary files being launched as empty tabs
Thumbnails of the site you’re about to visit
Get back to where you once belonged
Edit CSS. Disable Styles. I use this daily.
Stop firefox opening PDFs inline
Because you still have to test it
Happiness is a configuration window.