I'm a huge believer in podcasts. (If you haven't already, check out Geeks&Beats, the weekly podcast I do with Michael Hainsworth of BNN/CTV).
The guy I listen to the most--and the guy who does podcasting better than anyone--is Leo Laporte. He's an old radio guy (actually, he still does traditional radio) whose TWIT network has become a formidible and profitable venture. Check out this interview with him conducted by Next Market.