Podcast for learning English, specially for improving listening. Different themes.
http://www.podcastdirectory.com/podcasts/28327

Podcast for students.
http://veryvocabulary.blogspot.com/
http://www.etseverywhere.com/

Podcasts for learning Spanish
http://www.discoverspanish.com/podcast.php Explanation about phrases and translation. There are some lessons and it is a very elementary level. It is perfect for people that do not know to speak Spanish.

I would use podcast for teaching English, ans specially for improvinf listening skills. I think that for many students it is difficult to understand spoken English, and this can be an excellent way.
Listening and download breaking news or things in which they are interested in.