Casting for Pods.

Whilst Doc C was seeing his doctor this morning, I sat in the waiting room knitting and listening to some hastily downloaded pod-casts.

I'm not sure I really understand pod-casts, are they like verbal blogs?  And how do you tell which ones you want to listen to?  I gave up a minute or two into a pod-cast by a British stand-up comedian that I used to like, but listened enthralled to three episodes of an Aussie bloke's adventures in knitting.

Am I doing it wrong?