The full list of Firefox extensions that I consider absolutely mandatory. All of these work with FF 2, and many work with older versions. All but one or two have also been updated to work with FF 3. (List last updated Aug 26, 2008.)
So a girl I work with just came running into my office, trying desperately to be discreet but clearly panicked. She was asking where to find an image on the hard drive that hasn’t been saved specifically, but that was emailed using Outlook.