AboutGoldenPod is a command line podcast client written in perl. It allows you to easily manage and download podcasts from the command line. It can download podcasts from standard RSS(-like) feeds, or it can attempt to parse any other cleartext document (ie. XML or HTML) for a list of audio files and download those. For users already using BashPodder, it can function as a more feature-rich drop-in replacement for it.
You can find more information about podcasting on Wikipedia.