Firefox new prototype add-on Personas can change the style and skin of Firefox quickly. After installed this add-on, there will be a little fox icon on the left bottom corner. Click that icon and you can choose some pre-set skins. Your Firefox will be changed with the skins instantly without restart. If you get bored about the look of this great internet browser, you should get one.

The Mozilla team who developed this plugin said they will soon develop a API for designers and developers to let everyone to create more themes. This add-on currently in prototype and beta testing stage. It already have Windows, Mac OS X and Linux version so you may wanna to try it out.