The best thing about podcasts from an educators perspective is that if you are 1-1 with iPads you can download them at school and have your students listen to them at home. In my class I had students go to Podcasts and download an episode of the Math-Dude on Graphing Parabolas, they took notes as they went along and completed a worksheet after.
There are lots of great podcasts for any classroom including history, art, and science.
Completely Optional Knowledge Podcast is a great, short podcast for interesting science questions.
Presidential provides short biographies and interesting insights on the history of presidents leading up to the election.
Stuff You Should Know is a general podcast that informs on a wide range of subjects. There are lots of great podcasts around and new ones become available everyday.
Next year I will try to incorporate this lesson, with the walking classroom.