If you have an iPod or any portable media player that uses the media transfer protocol, or MTP), you might be interested in the CastGrabber, a charger that can download podcasts and place them directly on the player without using a PC. It even works with iTunes.
As long as there's a network into which you can plug the $99.95 CastGrabber, you can grab your podcasts directly onto the player. All you have to do is set it up beforehand using a PC, and the next time your CastGrabber contacts the internet, it downloads your chosen podcast.
Even though we like its set-and-forget routine, which vaguely reminds us of a TiVo, it seems a bit unlikely that you'd have access to a network but you wouldn't have a PC nearby, but there must be some situations where you might be able to use the CastGrabber. For instance, what if you're a college student in a dorm with internet connections everywhere but you don't have a laptop? [CastGrabber]