I have been adding to my Firefox browser more and more extensions. Today, since it is Thanksgiving, a slow day, I looked around and added two more extensions:

The weatherfox/forecastfox extension places three small icons on the browser toolbar to show current, today, and tomorrow's weather. You can customize it to show more days, and more locations. it pulls the weather from weather.com.
The Web developer extension let you examine a HTML page, look at the forms, CSS, tables, and about one thousand other things. A must have if you are developing web application and need help (who doesn't) to debug your generated HTML forms and laouts.