Here is the podcast I built with Emily Newton. It's about how she uses Twitter in the classroom. This particular podcast was modeled after 99% Invisible (which has an emphasis on design).
Here is a great episode about money design.
For all the pop-culture and comic fans, I give you Superman.
And this is a student favorite about a broken window.
Another big podcast that I go to on a consistent basis is Radiolab. This podcast tends to delve into science topics more so than 99%.
Here is one about Beethoven. It's an inquiry about the tempo markings in his music. How fast did he really intend for the pieces to be played?
Here is another one from Radiolab about Noel Blanc. He's the voice for Bugs Bunny, Pork Pig, and Tweety.