I recently discovered this awesome podcast for learning Chinese called ChinesePod. This podcast actually makes learning Chinese fun, or at least, as fun as learning Chinese can be. The hosts are great, and the lessons are on interesting topics like pirated DVDs, love triangles, and infinitely recursive stories. There are lessons for each level of Chinese, from novice to advanced (I'm at the intermediate level).
Best of all it's free and there's no advertising in the podcasts. You can subscribe in iTunes for the latest episodes. You can also get the first 500 episodes via bittorrent.