Mozilla just released Firefox Beta 3. If you want to check out the latest beta build of the upcoming Firefox 3 browser you can download it here. They made some improvements to the buttons as you can see in the screenshot( don’t mind the square rocket buttons, it’s from my Netrocket extension). Memory usage issues have been resolved and some other bugs like the when you click on the blank side of a website, it highlights everything which I find annoying. Some plugins are still not supported including Google Toolbar. The only plugins that I have, that seemed to work in Beta 3 is Stumbleupon, Netrocket (as mentioned above) and Greasemonkey. This version still have a few bugs that needs to be fixed. You can just check it out here for the reported issues.
Note: This version is for testing purposes only.