I am using Sidetrack on my iBook, but I suspect that the 2-finger technique is better and easier. Nice idea by Apple, or whoever invented it. With Sidetrack, I get pretty reliable performance, but sometimes the up-down scrolling isn't recognized. The side-to-side scrolling is worse (even after re-calibration), bad enough that I typically use shift in combination with up-down scroll. For apps like Photoshop, the 2-finger scroll is much more versatile too (drag around in all directions, not just along 2 axises.) It would be nice if this was a universal feature in Tiger...please Apple???