Huge upvote for Carlos Bueno's Lauren Ipsum (aka HN'er aristus).
I first heard about this book on HN (http://news.ycombinator.com/item?id=2144526), when it was just a few chapters. I read them to my daughter, Laurel. She thought it was soooo cool and told him so. He actually wrote in a bit part about Lauren saying "My name's not Laurel!" and sent Laurel an autographed copy.
My kids went on to read the whole book with my parents over VTC (is that the category for FaceTime and Skype?), and it was a huge success. My mom happens to be a college math teacher and has turned a number of other faculty on to the book.
For those interested in this genre, there is also Computational Fairy Tales (http://computationaltales.blogspot.com/p/book.html)
