Armangil's podcatcher is a podcast client for the command line. It provides
several download strategies (new shows only, back-catalog allowed, etc),
supports BitTorrent, offers cache management, and generates playlists for MP3
player applications.

This application accepts one or more feeds (RSS or Atom) or subscription lists
(OPML or iTunes PCAST) as argument, in the form of URLs or filenames.
Alternatively, it tries to read one such document from the standard input.

WWW: http://podcatcher.rubyforge.org/