I am in need. I don't know if something like this exists. If it does, point me to it and I will want to buy it! If it doesn't, make it!
Wanted: an iPhone app or Kindle feature where you can read books and then when you get in a car or want to listen to them, you can switch to the audio version in the exact spot where you are in the book. When you're done with the audio, it will take you to that spot in the book where you finished and then you can keep reading.
How cool would that be?