To see an example of an interactive textbook please take a look at this free iBook. Released chapter by chapter and under the direction of famed biologist E.O. Wilson this iBook uses the capacity of the iPad to educate and enthrall you. This is the future of e-textbooks rather than the staid one-dimension conversions from print that most e-textbooks are today. You must have the iBooks app on your iPad to download this free iBook.