Apple was very proud to show its fancy page-turning animation for its iBooks app on the iPad and iPhone. The touch-gesture controlled motion would translate into a page flipping animation that would go as slow or quick as the user wanted. It's commonplace for Apple to incorporate little touches like that in its user experience – except Microsoft may have thought of it first.
In a patent application submitted by Microsoft on January 7, 2009 called "Virtual Page Turn," Microsoft describes:
One or more pages are displayed on a touch display. A page-turning gesture directed to a displayed page is recognized. Responsive to such recognition, a virtual page turn is displayed on the touch display. The virtual page turn actively follows the page-turning gesture. The virtual page turn curls a lifted portion of the page to progressively reveal a back side of the page while progressively revealing a front side of a subsequent page. A lifted portion of the page is given an increased transparency that allows the back side of the page to be viewed through the front side of the page. A page-flipping gesture quickly flips two or more pages.
What's described here is basically what happens for page turns on the Apple devices. Of course, there are other applications on the iPhone and iPad that also use this page turn animation, even before Apple adopted it for iBooks.
Time will tell if Microsoft gets ownership of this e-reading feature.