Podcasting is a system developed by former MTV host Adam Curry. He realized he wanted to have radio shows on his iPod that whenever he plugs it in, he would just get the latest version up, say, DAY TO DAY, so that wouldn't have to constantly go download things himself. So it's just an add-on piece of software that lets you subscribe to online radio shows or people who have playlists of new songs every day like Roger McGuinn's "Folk Den." And then you just see a playlist on your iPod and it would say, for example, DAY TO DAY and you'd press it and there would be the last few segments.

from: Analysis: Apple unveils new product by Alex Chadwick
source: NPR Special, 28 October 2004.
via: HighBeam Research