Just installed a new kernel extension to get that two-finger scrolling on an iBook G4. Works like a charm. The one that handles both methods is a little screwy because it switches to X/Y mode as you’re making circles and the scroll kind of jitters, so get both of them and test each one to see which you like better. I’ve found the X/Y one to be the best, which is also, coincidentally, the mode Apple chose for the new PBs.