A podcast is an audio recording that can be posted to the web and subscribed to by users. Adding video to the audio podcast creates a 'vodcast.'
You don't need an iPod to listen to a podcast - you can listen to podcasts on computers or any type of MP3 player. But because it is digital, you CAN upload it to your MP3 player and 'take it with you.' Increased mobility not only allows for more flexible and reinforced learning, but it also appeals to many of the digital 'natives' and those who appreciate technology!
http://www.how-to-podcast-tutorial.com/13-basic-podcasting-software.htm
http://etc.usf.edu/software/description/audio.html
http://etc.usf.edu/te_mac/movies/podcastingbasics.html
Integrating Podcasts Into Your Classroom - Colette Cassinelli - http://www.youtube.com/watch?v=ExkMeQfuLGc
Tips for Podcasting - Sue Waters' recorded slide presentation:
ESL Classroom Podcasting - Scott Duarte's slide presentation: