I stumbled upon this one by accident today. Did you know that you can navigate a spreadsheet in Documents-To-Go with the Jog Dial?

Sure, you can use it to scroll up and down, but try pressing the Jog Dial and then scrolling. You can move side-to-side! Press it again, and it reverts to up-and-down!

I’m sure this is documented somewhere, but I never would have known this had I not accidentally hit the Jog Dial.