I link to Under The Radar more than any other podcast for a reason. Both David and Marco have great insight and explain everything well. In this episode, they talk about how much app ideas are worth and what to do with them. Good stuff. Now when your friend approaches you with their great app idea, you'll know how to respond.
If you only have time for one development podcast a week, it would be hard to argue against selecting Under The Radar.
Under The Radar #35: Ideas from David Smith & Marco Arment