Communications and mainstream media are entering a new age of on-demand content. As digital video recorders, like TiVo, change how we watch television, podcasts are taking the spoken word in its own on-demand direction. Astronomy podcasts allow listeners to get up-to-date content on a variety of topics ranging from what's in the sky to what's in the news. In August 2005 and January 2006, we conducted surveys of astronomy podcast listeners and producers. Using the results of these studies, we examine how to create a podcast, who is listening, and how astronomy podcasting is affecting its listeners' attitudes toward astronomy. The article cites the "Slacker Astronomy" podcast as an example astronomy podcast throughout. (Contains 5 tables and 4 figures.)