Adblock Plus: why I use FireFox over any other browser

ForecastFox: put weather updates in status bar, extremely customizable

Download Statusbar: get rid of the annoying pop-up box and watch downloads at the bottom of the browser

If you're on a laptop with a small screen right-click and hide the menu bar, you can bring it up by taping <Alt>

DownThemAll!: download all images/movies/songs/pdfs in a page

They are insanely useful if you