What is podcasting?

A podcast is audio you can carry in your pocket — portable, time-shifted, on demand. It's any audio on the Internet that you can subscribe to and download to a portable device (like the iPod, hence the unfortunate name) or computer.

Webcasting, where music or audio is streamed, is not podcasting.

Some folks use the term "Internet radio" to refer to podcasting. But Doc Searls has written persuasively that podcasting should not be equated with radio — mostly for political and public policy reasons.

Radio is mass media. It generally caters to least common denominator programming. It's delivered on the programmers' schedule. And, most significantly, its content is regulated by the federal government.

Podcasting is personal media. It caters to individuals. Its most salient feature is that you can download podcasts to listen to on demand — on your schedule. And it's utterly unregulatable.

Podcasting was born in November 2004 and gained significant uptake last year, with thousands of podcasts and millions of subscriptions on services like Apple's iTunes.

Quite a few people are both vloggers and podcasters, although most folks gravitate to one media form or the other. I'm more of a visual person, but I'll be posting podcasts here as well.

If you're thinking about podcasting, you should consider joining Ourmedia.org. The nonprofit service will host your podcasts for free, so you never get socked with bandwidth bills from your Internet Service Provider if you happen to upload a file and it becomes wildly popular; for example, my friend Glenn ran up $10,000 in bandwidth bills for book chapters he placed online.

Check out services like the Podcast Network, Indiepodder.org, Podshow and Podcast Alley for directories of popular podcasts.