Please note: you'll probably need to install the Status-4-Evar extension to restore Firefox's statusbar, which Mozilla recently decided to remove.
FoxClocks lets you keep an eye on the time around the world - or just your local time - by putting small clocks in your statusbar. Choose from a set of useful time formats or create your own - custom formats are easy to create and very flexible.
You can set each clock's colour, or even have a clock change colour during certain hours (perhaps green when it's a good time to Skype your friends in Japan). Too much stuff in your statusbar? Move your clocks to a toolbar, or switch to 'icon' mode and hover over the FoxClocks icon to see your clocks.
FoxClocks' Zone Picker tree lets you browse virtually all the world's time zones by country, region or city. Enable automatic database updates and you'll always have the right time.
If you have Google Earth, FoxClocks can take you to any location in its database: don't know where Budapest is? Right-click on it and choose 'Google Earth...'.
FoxClocks is available in English (British and US), Belarusian, Chinese (Simplified), Czech, Danish, Dutch, French, German, Hungarian, Italian, Japanese, Korean, Mongolian, Norwegian (Bokmål), Polish, Portuguese (Brazilian), Russian, Slovak, Spanish, Turkish and Ukrainian.