Check out this great interview with John Piper, here, here, and here. Here’s one snippet:

Adrian
We have just been talking about studying the Word, and obviously books, but I guess for most preachers, they like to listen to other preachers as well. I guess you’re probably no exception to that. So who have you got on your iPOD that you’re actually listening to?

John
I do have an iPOD. It happens to sit in my speaker base in my bedroom as kind of an alarm clock. But my computer is in my study, and my treadmill is in my study. That’s the only time I ever listen to preaching—when I’m running. So three times a week, for thirty minutes or so, I’m listening to other people speak. So I download them from the Web, usually. Who are the last ones I listened to? I listened to [Don] Carson. I listened to R. C. Sproul. I listened to Martyn Lloyd-Jones. Somebody gave me the whole series of MLJ on Romans. I listen to C. J. Mahaney. I listen to John Sailhammer on the Old Testament. I listen to Carl Trueman on, what’s the topic? I can’t remember. A little while back. Basically, I’m looking for two things—one, contemporary relevant issues that I might want to dig into, or model preaching. So, whoever at that point, and they’re not always the same people, the model preachers and the ones who are talking about the things I feel like I need to get to know about.