I stopped using Firefox about a year ago and switched to Opera permanently because Firefox started taking up too much CPU on my machine as well...i think it has to do with how it interacts with libc...anyway, I'm sick of FF crashing constantly.

I usually have 20+ tabs open in Opera hehe but it handles memory so efficiently that I never have problems on my 2.6GHz, 768MB RAM Intel machine.

I wish they'd make a Linux version of Google Chrome...I'm dying to try it out...I did try it out once ages ago on my sisters laptop but it's about time a Linux version came out!

So right now, I only use FF for testing sites and in case I need to use Firebug to debug some AJAX calls but other than that, it's all about Opera.