This article features two high school chemistry teachers, Aaron Sams and Jonathan Bergmann, who have overturned conventional classroom instruction by using video podcasts to form the root of a new learning model. Thumbing through an issue of "MacWorld" a few years ago, Aaron Sams was struck by an article about an application called ProfCast that allows instructors to record live classroom lessons on a Mac. He brought the story to the attention of his fellow Woodland Park High School chemistry teacher, Jonathan Bergmann. The two men both saw that the ability to capture their daily lecture as a video podcast-- or vodcast-- and then allow students to view the recording on their own schedule later that evening could be the solution to a nettlesome yet unavoidable problem they were facing. They share their video podcasting advice at Educational Vodcasting and Learning for Mastery. They implemented what they named a "mastery learning model," which allows their students to work through the material at their own pace. The two teachers acknowledge that quantifying the results of this coordinated move to vodcasting and self-directed learning is nearly impossible. They both say that the real impact of the mastery learning model has been to put them in closer contact with their students.