I'm always surprised to hear that many people have no idea about podcasts in general and cycling podcasts specifically. Lots of interesting stuff out there.

I've been listening to the Fredcast for about two years. Also listen to:

Two Johns Cycling Podcast
Bicycle Radio
Competitor Radio
T-Chatter (Terry Bicycles)

You'll find them all at Itunes and they all have their own websites with archives as well.