Ask HN: Writing an iPhone dev book for teens -- would love to hear thoughts.

I submitted a proposal to write an iPhone book for non-devs (or novice devs). I am targeting it to teens (thinking about the kind of book I would have wanted when I was a teen and hacking my C64). I have spent some time watching _why's videos and playing with HacketyHack, but ultimately, I have to explain iPhone development (although I gave some thought to making a super-simple app framework, that's probably not going to fly as a book). I expect to supplement with a website that would point to more information -- the book is about teaching concepts and getting a few simple apps done and explained, not being an exhaustive reference (or even a very good one). Would love to hear any thoughts people have had on this topic.