If you have FF2.x, and click on your update link, it will prompt you to download ff3, and redirect, I done so recently.
FF3 is about 7MB download, mozilla claims quite a few improvements, so get it.
I do get an irritating nack(habbit that freeks you out) with it, sometimes when you have a lot of tabs open, it just jumps off your Pc, and kills itself. Rather irritating, especially if you are researching something and don't want to be interrupted.
I hate that, otherwise it's decent. I would say better than IE.
I also use thunderbird for e-mail, like the way you have your identities laid out vs. outlook/express.
If you are thinking of using incredi-mail, think again, it sucks and non-power users love it. Yuck.