Useful article, Chris. I use a silo podcast reader (Beyond Pod), and have never considered before that podcast listening could have a social and crowdsourcing angle. Another thing for me to add to my indiewebify list!
I see you listen to TWiG regularly: I sort of lapsed regular listening after Gina Tripani left but still listen when Kevin Marks is on. The one thing I never miss every week is Security Now with Steve Gibson, such a great resource.