Feel free to add to this list of interesting Podcast Examples, as they may prove useful as future examples of the form, and in the meantime could provide hours of informative listening.

This American Life on NPR

"If you like radio, you have to admire how Glass has breathed new life and personality into the art form, how his interviews with and documentary segments about unfamous, unimportant people have made such obviously good use of this homely, intimate, person-sized medium that it’s impossible to believe that no one had done anything like this show before 1998. If you don’t like radio, you might still like This American Life."
This American Life and the Illusion of No Illusion

Spark on CBC

Spark is a weekly audio blog of smart and unexpected trendwatching. It’s not just technology for gearheads, it’s about the way technology affects our lives, and the world around us.

How Stuff Works Podcast