If you have a laptop that supports multitouch gestures, you probably are aware of the fact that a three-finger swipe in Preview will go to the next or previous page in a PDF. But you may be annoyed at how Preview insists on animating each page switch with a small scrolling action. This can make it very slow to scroll through a document -- almost as slow as regular two-finger scrolling.

Fortunately, there is a solution: use a three-finger swipe in the sidebar. When you swipe in the sidebar, the pages will change instantly, without any animation. This works no matter what mode the sidebar is in (table of contents or thumbnails). And if you are in contact sheet mode, three-finger swiping will navigate you through the contact sheet.

I can only test this in 10.6, and I didn't discover it until I was running 10.6, so I don't know if it works in 10.5 or not.

[robg adds: My MBP is also 10.6-only now, so I can't test in 10.5 either. If you can, please post in the comments.]