I just got an email with info about several audio recordings on sale at Christian Audio (www.christianaudio.com) this month. I have a friend who's family has really enjoyed the Jonathon Park series--which is why I paid attention to the ad. Now through July 31st, the Jonthan Park sets are on sale at the site for $5 each for download. That's a great price if you like the series. Several books from the Box Car Children series are also available the same price.
Also, on the site is a free download for this month for The Sword. I have really enjoyed this series. I just received the third book in the mail this week and will soon be writing a review of it. It isn't for children under 15 in my opinion. It would be great listening for a commute on the way to work, though. It falls under the category of "dystopic fiction". It is an anomaly for my reading, but the writing is so good that it is a thoroughly engaging and interesting story!