Many thousands of radio episodes are available for download at the Internet Archive:
http://www.archive.org/browse.php?fi...=radioprograms
Just right-click to download an episode or a collection.
The number after each program name in the index refers to the number of collections of that particular program. Each collection may contain dozens of episodes.
Old Time Radio (OTR) programs are particularly suitable for the MP3 player in ebook readers because individual episodes don't take up much space. That's because the episodes were fairly short. Some programs ran for as little as 5 minutes (e.g. Five Minute Mysteries). Others ran for 15 minutes and some for 30 minutes. The commercials are interesting too although I cringe when I hear the radio commercials extolling the benefits of smoking a particular brand of cigarette.