If you want total control over how the overall interface of Firefox looks, then Personas for Firefox is the extension for you.
Personas is so good in fact, that Mozilla has decided to include it as standard in the latest release of Firefox 3.6. Personas makes applying themes to Firefox as easy as changing your underwear. This means you don't have to go hunting high and low over the Internet and download themes individually. Personas makes the whole process much simpler.
When Personas is installed in your add-ons, you'll see a small button in the lower left corner of your browser window. Every time you want to apply a new theme to Firefox, simply click on this button and select it from the context menu. There are about fifty themes to choose from and expect this to expand dramatically now that Personas is an integral part of Firefox 3.6. Themes are divided into categories such as Firefox, Holidays, Nature, Scenery, Sports etc to help you find something that fits your current mood.
Note, however, that some of the themes aren't that practical. For instance, some of them are rather elaborately designed so that it can make reading the menu bars a bit tricky. What's more, the themes only change the main window's appearance – icons and other menus remain the same default Firefox design.
It says something about Personas that Mozilla has decided to integrate it as standard in Firefox 3.6. Give it a try and you'll see why.
