EVEN FOR APPLE INC., which has thrived on taking risks, the iPhone represents an audacious bet possibly its biggest ever.STERLING HEIGHTS -- Molly Zapinski will get the chance to do more than listen to her favorite tunes on an MP3 player next year -- she'll also be able to curl up with a good audio book from school.EVEN FOR APPLE INC., which has thrived on taking risks, the iPhone represents an audacious bet possibly its biggest ever.