Many newspapers and magazines produce science podcasts. You can set up your RSS reader to automatically download podcasts so that you can listen to them later. Here are a few examples of science podcasts:
NY Times Science Times Podcast (weekly, Tuesdays)
Nature Podcast (weekly, Thursdays)
Nova Podcasts (choose your download preference and enjoy!)
National Public Radio Science Friday (or streaming audio is here)
CBC Quirks and Quarks
CBC White Coat Black Art
Many science journals and magazines also have video sections on their websites. For example:
Test Tube documents the “highs and lows of life as a scientist” in videos.
For a short video about each of the chemical elements, visit the Periodic Table of Videos.