iTunes has a podcasting feature called MobiStories Virtual Picture Books. Kids can play these virtual stories on a Video iPod, cell phone, PSP or DVD. I found that MobiStories is mostly for children ages 2-8. A huge plus about MobiStories is that they are free to download!
If you happen to find a favorite read aloud, this may be a great tool to use in the classroom during snack time or even as a component of a listening center. The stories have excellent story tellers with a variety of sound effects.
You can also access MobiStories through iTunes.