You can even choose to sign something other than a blank page:
Authors are no longer restricted to signing a blank page. Autography's solutions include graphic-rich, customized signature pages that extend the author's brand beyond the book's cover. Authors can also elect to autograph a picture, taken at the event or from a stock menu, and insert that into their ebook.If this intrigues you, visit their website. You can also watch a video explaining how it works. Note: the video is not easy to hear.
Has anyone tried Autography? What do you think of the idea, either as an author or as a reader?