One Firefox extension I have no intention of uninstalling is SessionSaver. SessionSaver keeps track of the state of your browser — window positions, open URLs, scrolling positions, even tab-histories — and will restore them whenever you restart the browser, even if Firefox crashed. Next up is to install it on my wife’s computer — she keeps a lot of Firefox windows and tabs open, which really sucks for her every week or two when Firefox or an errant plugin finally freezes or blows up.