The following links are relating to audio and video podcasts that are for Scientific Education:

Radio National's The Science Show
http://www.abc.net.au/rn/scienceshow/default.htm

CSIROpod
http://www.csiro.au/products/CSIROpod.html

Nature Journal Podcast
http://www.nature.com/nature/podcast/index.html

ABC's The Lab - Podcast
http://www.abc.net.au/science/programs/podcast.htm

The Naked Scientist Podcasts
http://www.thenakedscientists.com/HTML/podcasts/listen/

Newscientist Podcast
http://www.newscientist.com/podcast.ns

Scientific American
http://www.sciam.com/podcast/

Chemistry Demonstrations and Videocasts
From Exploscience.com (a commerical site but lots of FREE vids as well)
http://exploscience.com/explosciencewebsite2/Video_Page.html

Science Misconceptions explained on Podcasts
http://science.ocde.us/Podcasts_and_Videocasts.htm

BBC GCSE Bitesize Podcasts
http://www.bbc.co.uk/schools/gcsebitesize/audio/science/index.shtml