The Elgg team launched Elgg Radio with their first podcast, an excellent interview with George Siemens (12MB mp3). It sounds like they're also planning a good lineup of future guests.
I'm still not the hugest fan of audioblogging as a way to transmit and glean information, but there is something nice and personal about hearing people speak in their "real" voices. George is one smart cookie, and Dave keeps him loaded up with solid questions. You get the impression that they could have easily turned half and hour into six hours of discussing these topics.