I have installed Mozilla Firefox 3.6 Beta 2 and enjoying using it. Its ‘persona’ feature is really cool! With one click you can install and use it. When you visit persona section you get a lots of personas so far. Take you mouse over the persona image, and your browser’s look is changed! What a live preview. Other changes to Firefox are not that much visible. I am fan of Firefox and using it for more than 2 years. In fact, I have not installed and tried IE8, after using Firefox.
You can get the beta of Firefox 3.6 from here: http://en-us.www.mozilla.com/en-US/firefox/3.6b2/releasenotes/. Have a look at it.