If you're planning a trip and are looking for some inexpensive spoken books, iTunes put up a special 25 books for under $5
page that you might want to check out. These audio books include material ranging from Steven King and Jerry Seinfeld to Elie Wiesel and Ann Coulter. Be aware that most of these selections are abridged or based around short material, so there's generally a good reason they don't cost as much as most full-length audio books. The cheapest item, Harry G. Frankfurt's "On Bulls**t" (Apple adds even more asterisks than I) costs just $2.95 for an hour's frank discussion.