I have been using Mozilla Firefox browser now for about a week and I would have to say it is totally cool. There are some bugs tough. Opening PDF’s seems to crash it. Also, if I opened links within my RSS Aggregator or Outlook 2003, it would act strange and one IE and one Firefox browser would open (I have Firefox set as default browser).
I found a link to fix the second problem:
Steve Novoselac's Blog 