Free audiobooks for a road trip

This weekend is Memorial Day Weekend, considered to be the unofficial start of summer in the U.S. Although the price of gas may prevent me from going on one this year, road trips were always part of my summer in past years. Long drives are a great time to take in an audiobook, but also require a specific type of book. The plot has to be exciting enough to hold my interest on boring stretches of the Interstate, but simple enough that I can still pay attention to the cars around me. Thus, I've come up with 5 recommendations for road trip audiobooks:

• For blockbuster action fans: The Prisoner of Zenda (my review)
  
• For light comedy fans: Right Ho, Jeeves (review)
  
• For people who like variety: The Adventures of Sherlock Holmes (review)
  
• For traveling with children: The Wizard of Oz (review)
  
• For traveling with people who don't like audiobooks: Black Jack Justice

This last one bears some explaining. The folks at Decoder Ring Theater produce an excellent show in old-time radio style about the adventures of a pair of private investigators. It's PG-rated and full of great sound effects and jazzy background music. I haven't reviewed the shows before since it's not an audiobook, but it's worth downloading a few episodes for your next road trip.