ISBN: 0553379658 Unbeknownst to the narrator of IshmaelBook, a second pupil responded to the ad in the paper ("Teacher seeks pupil. Must have an earnest desire to save the world") -- twelve-year-old Julie Gerchak, whose interaction with Ishmael results in a dialogue strikingly different from the one found in Ishmael...
More info and some excerpts can be found at http://www.ishmael.org/Origins/My_Ishmael/
An excellent book. Less rigorous than IshmaelBook, but more entertaining. It appears to be written for the younger generation.