The first site I came across Ecogeeks at the link http://www.thewildclassroom.com/home/nav/subscribe.html
It seems lime some of the information is age appropriate and content appropriate.
The second podcasts site is called EPN or educational podcast network
The third podcasts includes 60 second podcasts
The fourth podcasts includes several links to podcasts
While looking for podcasts, I found a great RSS subscription feed at ASCD on Technology, thought you all may like, here is the link to the webpage:
The RSS feed links are down on the right sidebar (I LOVE Google Reader, BTW, for subscriptions).
ASCD's podcast topics look interesting as well, but were not in subject areas I was looking for.