Firefox, the little browser that could, shipped the offical version 1.0 today. You can try to get it at Firefox but that site is getting hammered. So, while you are waiting for your download to begin, why not read about some extenstions that people besides me find helpful? BTW, an extension is just an add-on that extends Firefox's functionality. I haven't tried all of these so caveat emptor.
PS: Congratulations Firefox team!