An Apple patent (number 20120240036) for an e-book reading location indicator has popped up at the U.S. Patent & Trademark Office.

To help a reader of an electronic document, e.g., an eBook, find his or her reading location following a repagination event, an electronic reader application executing on an electronic device displays a first portion of content of the electronic document, detects that the reader has performed a predetermined action that triggers repagination of the electronic document, and repaginating the electronic document to cause the reader application to display a second portion of content of the electronic document, the second portion including at least some of the first portion of content and at least some newly visible content of the electronic document, such that the newly visible content appears visually different, at least temporarily, from the first portion of content that remains visible.

Here's Apple's background on the patent: "Much like an ordinary printed book, electronic books, or more generally, electronic documents, can be used to present text and pictures to readers. Instead of ink and paper, however, an electronic book is a collection of digital data that software, known as an electronic book reader application, can interpret and present on a display. A variety of devices run electronic book reader software such as desktop and notebook computers, eBook readers, smart phones and/or other mobile devices. One available format for eBooks is defined by the 'ePub' standard, which is maintained by The International Digital Publishing Forum (IDPF)."

The inventors are Joe R. Howard, Alan C. Cannistraro, Scott A. Grant and Timothy B. Martin.