I'm quickly catching the podcasting bug and subscribe to several podcasts via iTunes to listen to on my iPod while walking or working out. The following are some good business podcasts and are all available on iTunes, which is free to download . You can listen to all via your computer; there's no need to have an mp3 player or iPod. These just provide a flavor for what's out there. Browse through the business podcasts at iTunes for many more (click on "podcasts" in the iTunes Store).

• American Public Media Marketplace
http://marketplace.publicradio.org/pm.html
• BusinessWeek

http://www.businessweek.com/search/podcasting.htm
BW provides a variety of podcast shows. I had difficulty accessing from their webpage but no problem via iTunes which organizes their podcasts nicely.
• HBR's IdeaCast

http://www.hbsp.harvard.edu/b01/en/hbr/hbr_ideacast.jhtml
• The Wall Street Journal

Provide a variety of podcasts. iTunes is the easiest access point.
• Coffee Break Spanish

Okay, this isn't a business podcast, but what better way to learn spanish in a few minutes every day!
Available in iTunes.