Page Flip, in short, is basically the digital equivalent of sticking your thumb between two pages and scouting through the rest of a book looking for the juicy bits. If you're using the Kindle app on a tablet or phone, tapping on a page gives you a zoomed-out view of that page, along with a progress bar along the bottom to mark your place in the book.

While you flick through the pages, a little window remains in the corner of the screen -- that's the page you just came from, and one tap brings you back to where you left off. If that doesn't get you skimming through prose fast enough, there's also a grid view option that shows off even more pages at once. Even better, page previews -- be they big or packed into the grid -- change on the fly when you fiddle with your margin, line spacing and typeface settings.

Getting Page Flip to work on Kindles was a little trickier, considering the differences in displays, refresh rates and touch sensitivity. Still, the concept scales to these more basic devices without much trouble -- you'll be able to pin pages and view the grid (albeit with less detail), and there is a pair of new shortcut buttons to help you jump between chapters. Simple enough, no?

I didn't spend much time with Page Flip, but there was one thought I couldn't shake while I was seeing it: this would be kind of amazing to have before you buy a book. After all, who among us Luddite bound-book readers doesn't thumb through a tome before trudging up to the checkout line? When asked, a pair of Kindle product managers declined to answer directly; they mentioned the "Look Inside" feature on book listings has been "really helpful," so I wouldn't expect much more than that for a while. Speaking of book listings, I haven't been able to find a book that isn't Page Flip-enabled, though Amazon concedes that not every digital book they carry is compatible right now.