I will post these here in reply to a personal message from the OP to help others that may be looking for them also. There were a few threads a while back about decent podcasts but here's a list I have on my itunes.
You can download itunes free here
http://www.apple.com/itunes/download/
All of the podcasts I have are available through itunes for free and some are available for download through websites if you prefer a different music player. In itunes go to the itunes store, click podcasts then click science and medicine and you can browse a full list of medicine related podcasts that may be of interest to you.
PHTLS podcast
http://www.phtlspodcast.com/
Medic Cast
http://www.mediccast.com/ there is one series directed at field medics, the same guy also does a nursing podcast, I listen to both.
Others that I enjoy listening to through itunes include:
Biology 4120/4220, it's an entire college level A&P course that the instructor has put on itunes.
American College of Emergency Physicians (ACEP) has a podcast, above our level really but good information.
Emergency Medicine Lecture Series, again directed more at hospital providers but some good information to be had just learning disease processes and such.
EMS: Pharmacology for the prehospital professional, some good information but not nearly as technical as some of the others. Seems much like our entire education and EMS specific podcasts are very elementary.
Medpod 101/ learn medicine, another good one for learning disease processes, again pretty advanced but that's a good thing.
The Merck Manual of patient symptoms, everyone probably knows about the merck manual, this is pretty much a book on tape of that.
There are others but those are the major ones that I listen to.