I recently finished recording a three-part podcast series on the book of Joel. This series is part of a year-long project that I've been working on in conjunction with SBS international (the conglomerate of all 55 + Inductive Bible Study schools like ours across the world). The goal is to post free audio lecture files online for every book of the Bible. These Joel lectures can be found online at "www.thesbspodcast.com." The podcast site is recording thousands of downloads a month! Yes thousands! People are hungry for solid Biblical teaching!
Click on the above title "Joel podcast episode 1" to listen in.