I installed now the newly released Firefox 3.5 and I am impressed. I think it is about twice as fast as the 3.0 version. I had also recently tried Chrome but had noticed significant stability issues when I had many tabs open and the speed also seemed to suffer. For some reason I never used Opera other than checking it out briefly. No idea why, but I guess the web surfing experience on the mobile – prior to the iPhone coming on the market – was so bad that I simply did not want to try it out on my laptop, too. And then of course there was always Firefox.