Podcasts are one of the technology tools de jour. Whether it will stick around for the long haul is up for debate, but for right now there are a number of ways they can be used effectively.
Advertise your opportunities
One way is to use podcasts as another way to get the word out about your organization and career opportunities. One firm that facilitates this is jobsinpods. Check out this example of how this content is already becoming popular in Google searches.
Gather job information
Another way to use them is to gather information about positions, say as part of a job analysis. Take a listen to this example, "Life as an Escalation Engineer" with Microsoft. I think you'll find it's a rich source of information about typical tasks and job requirements.
Can you think of other ways to podcast?