A number of items have crossed my desk that lead me to conclude that podcasts are growing more and more interactive, a neat trick for a medium that has been decried as nothing more than glorified downloadable audio.

The most recent of these items comes from the Church of the Customer blog. Ben McConnell notes that NPR, with its 300-plus podcats, is looking at developing a Web 2.0-like community for listeners of its online audio content. McConnell was speaking with NPR’s Eric Nuzum, who told him “the new vision is to create listener communities who would congregate on the site because of the 304 podcasts the broadcaster offers.”

I read this on the heels of hearing from Neville on today’s installment of For Immediate Release about a new podcast offering called Waxxi. Waxxi kicks off its business on Saturday with a live podcast featuring Naked Conversations authors Robert Scoble and Shel Israel. By “live,” I suspect the Waxxi folks will record the call-in show and make it available as a podcast.

If that’s the case, it’s an interesting model for a podcast, but it’s also one that Chris Pirillo, the force behind Lockergnome and Gnomedex has been doing for some time on his podcast. The very first thing you see at the top of Pirillo’s podcast blog are these three bullets:

• Listen to us stream live every Thursdaynight at 6pm in Seattle (GMT-08:00)
• Join us in the chat room anytime
• Call 1.888.PIRILLO to participate in the live broadcast

I was also wondering if you couldn’t just record a Skypecast conference and offer it up as an interactive podcast.

Michael Butler of the Rock ‘n Roll Geek Show has also done the live chat thing while fans listen to the live stream of the recording.

But whether Waxxi’s model is new or just an extension of ideas already employed to lesser degrees elsewhere is academic. The point is clear: Podcasts—a social media phenomenon in their own right—are melding more and more with other elements of social computing to become community-driven, interactive vehicles, even if they ultimately do remain nothing more than MP3 files.

In any case, I’m signing up to participate on Saturday just to get more information on Waxxi and how it works.