Futuremark has released a free benchmark utility which compares the performance of various Internet browsers on your system. That is a great tool. You can benchmark your system from here.
[url=]http://service.futuremark.com/peacekeeper/[/url]

Brilliant, thanks for the heads-up!
Like a few others on the Futuremark forums, I doubt I'll be changing browsers (from Opera) as a result, but I did download all of the major ones to benchmark, and gave them all a shot.
I was surprised by the results: Google Chrome is much more powerful than I expected, and Safari is pretty quick as well (but it *feels* slower).
I look forward to them releasing more detailed results as more benchmarks are done.

What a strange test, but defiantly useful. I think I'll stick with Firefox though, as I have too many add ons which I've become far too reliant upon.
I got a score of 443, so seems okay.

It strikes me as more of a PC test than a browser test. It isn't actually determining which is the fastest browser, its just determining which one runs faster on your system. Radically different hardware produces radically different results. On my system, FIrefox 3.0.7 ran faster than anything else (Chrome, Safari, Opera and IE followed in order). Still, at least now I've confirmed I'm using the right browser for me.