Podcasting allows you to receive pre-recorded audio programs on your computer, your MP3 player or smartphone automatically.
You "subscribe" (for free) to the feeds you want, KMTT for instance.
Your podcasting software will check periodically for any new audio files that become available
and download those files to your computer - or directly to your audio player if you prefer.
You can then carry hours of audio programming to help you through your commute, your work-out, or your downtime.