An anonymous reader sends this quote from the NY Times Bits blog:
"If you want to know just how broken the patent system is, just look at patent D670,713, filed by Apple and approved this week by the United States Patent Office. This design patent, titled, 'Display screen or portion thereof with animated graphical user interface,' gives Apple the exclusive rights to the page turn in an e-reader application. ... Apple argued that its patented page turn was unique in that it had a special type of animation other page-turn applications had been unable to create."
The article doesn't really make it clear, but this is for the UI design of showing a page being turned, not the actual function of moving from one page to another. That said, the patent itself cites similar animations
in Flash from 2004.