Color me surprised by the "zippy" comments--Safari 2 on Mac OS X 10.4.9 is by no means a speed demon, at least compared to the other options out there (e.g.
Firefox,
Camino, or the unofficial
G4-optimized build of Firefox that I run). That said, I haven't downloaded the Safari 3 beta yet--standard Apple practice for me is to wait a day or two for any The End of Life As We Know It issues to hit the blogosphere before I take the plunge--so your mileage may vary.