A quick heads up. We've now started rolling out our new iPhone app. It will let you listen to audiobooks, university courses, foreign language lessons, and other intelligent content on the iPhone. The app is free. And so is the content. So there's nothing to lose by checking it out.
We've designed it so that all media files open in native iPhone software — iTunes, Safari, the YouTube player, etc. You will need wi-fi (Apple says so) to download the content. This app, which was very generously developed by Fred Hsu, is a work in progress. Don't hesitate to give us feedback. And, if you don't mind, please leave a nice review/rating in the App Store and spread the word. Get it here.