I alluded briefly to the newish phenomenon of pod-casting in one of my 2007 articles, Dissect Medicine (New Zealand Doctor, 6 June 2007).

Podcast-ing became popular back in late 2004, largely due to the automatic downloading of audio onto portable players and personal computers.

Led mainly by the youth consumerist market (aka iPods etc) podcasting technology was picked up by some of the journals and a number of other medical CME-oriented sources using the same rather clever technology.

Thus, podcasting is a method of publishing audio broadcasts via the internet, enabling users to subscribe to a feed of new files (mostly MP3s) which can be downloaded to a device or PC. This is in contrast to direct video and audio streaming resources (such as news feeds) where downloading is usually not possible and thus access is only PC based and must be directly web browser managed.

Podcasting is perhaps distinct from other types of online media delivery because of its subscription-type model, which uses a feed (such as RSS) to deliver an enclosed file to a dedicated PC-based email folder or a remote archive such as Google Reader.

Podcasting enables independent producers to create self-published, syndicated "radio shows" (usually lectures or clinical conversations in the medical podcasting arena).

In the more global informational and entertainment-oriented sense, podcasting also gives broadcast radio programmes a new distribution method.

Google Reader is a great device for getting some order out of not just print content on the web, but also all those available podcasts - check it and subscribe through the Google NZ website

Listeners can subscribe to feeds using such "podcatching" aggregating software as iTunes which periodically checks out and downloads new content automatically (ie, silently, without effort and mostly even without filling up our email boxes). Some podcatching software is also able to copy or synchronise podcasts directly to portable music players such as the iPod. Indeed, one of my teenagers recently donated his "old one" to me which - apart from making me feel transiently some 15 years younger - means when I go to the gym now nobody really knows if I am listening to Bob Dylan, Red Hot Chili peppers or Johns Hopkins Medicine.

Any digital audio player (and of course not just iPods) or computer with audio-playing software can play podcasts. The same technique can deliver video files (and also slide-type presentations similar to Power Point presentations) and, since 2005, some aggregators have been able to play video as well as audio.

"Podcasting" is a hybrid combination of "broadcasting" and "iPod". The term can be misleading since neither podcasting nor listening to podcasts necessarily requires an iPod nor any portable music player. For that reason, various writers have suggested reinterpreting the letters POD to create "backronyms" such as "Personal On-Demand."

With clinical podcasts we perhaps needn't go to (quite so many) medical meetings or chase journal abstracts to get up-to-the-minute medical news and opinion from leading authorities. As GPs we are more likely to want to be getting review-type podcasts rather than research-oriented publications and some of the preferred sites are referred to later in this article.

So any time we want - while sitting at our desk, riding our bike, working out at the gym or on the garage treadmill, or perhaps most likely waiting on clogged motorways (for those north of the Bombay Hills at least) - you can listen to free, radio-style shows delivered via the internet to your iPod or similar personal audio player or your computer.

One such clinical podcast example is "Conversations in Medicine" which lets us imagine ourselves at an annual not-at-Rotorua conference chatting with someone you would otherwise hear only from a podium or lectern. And, we can do it when and where we want.

Probably potentially one of the best of the medical podcasting resources is at Harrison's Online. This is administered by the publisher of Harrison's
McGraw Hill through their excellent podcasting site at Access Medicine.

Access Medicine offers a variety of no charge review topics and in-depth podcasts - but users will need to subscribe (by clicking on the big iTunes microphone icon) to get the best value. Some of the podcasts can be up to 40 minutes in length and, while perhaps taking a while to download, are of high quality.

While the frequency of new content might fluctuate, McGraw Hill is still to be congratulated on its positive approach to accessibility. Many would contend this approach serves to increase their user support base - and ultimately their overall business success. For owners of a recent Harrison's text and subscribers to Harrison's Online there appears to be a wider range of podcasts available.

Another high quality US-based site for clinicians, the Johns Hopkins Medicine Weekly Medical News (Johns Hopkins PodMed) is administered by the Johns Hopkins University School of Medicine in Baltimore.

This provides a range of weekly updated 10 to 15-minute podcast chunks which are highly informative and quite different from those weekly summaries of content offered by the major journals. See JHM PodMed at www.hopkinsmedicine.org/mediaII/Podcasts.html

A UK-based portal site called My Medical Podcasts offers a good range of links to a selection of podcasting sites. Many of the general medical sites listed at My Medical Podcasts are consumer rather than CME-focused but there are also a range of specialty sites such as the American Heart Association though, curiously, the only free access podcasts are for consumers unless one is a member of the AHA.

Another site called Clinical Pod Cast is very good but is limited in its range of general podcast topics (Conversations in Medicine) and for some reason only has one specialty topic of Ophthalmology.

There is another site run by CME Outfitters called CME Podcasting. This has a limited range of clinical topics, and is mainly oriented to psychology, psychological medicine and psychiatry.

Audio Medica started out its life in 1992 as an audio CME provider for the American Society of Clinical Oncology and has since then teamed up with the British Cardiac Society, the European Society of Cardiology and the American College of Cardiology. Their evolutionary podcast site has a lot of more specialist level research-oriented content. You can try out this free oncology and cardiology-predominant site at www.audiomedica.com

And, for that little bit of almost painless clinical anatomy-refreshment, check out the University of Cambridge site. This site is quite unique and was started by a retired paediatric urological surgeon Robert Whitaker. After retiring in the 1980s and having "retrained" himself in anatomy he began teaching clinically applied topographical anatomy to first-year medical students at Cambridge and later clinically applied anatomy to surgical, radiological and other specialty trainees.

There are some really nice little podcasts and slide-audio podcasts reviewing such topics as neurology and neuroanatomy - some might argue one of the more important components of anatomy for day to day general practice and the challenge of "intelligent" pain management.

And, finally, for a broader "less than medical" experience, there are probably a large number of podcast libraries but you could maybe try the one out at www.podcastdirectory.com

The podcast providers referred to in this article are just a brief selection of some of the sites available. If you have a wet, stormy autumn weekend, you may want to have a look around Google for yourself, perhaps searching under "medical podcasts".