Dr. Shaffer has also presented a few of his lectures using Podcasts and have assigned students in a few of his classes to do this for one lecture. To do this, the students summarize the key concepts of the lecture and provide some pertinent examples, either those presented in lecture or in the book, or those thought up on their own. They then digitally record their summary using free audio recording and editing tool known as Audacity, and submit it via e-mail. These Podcasts are put on a website, where they can be accessed by other students. They can be downloaded onto mp3 players, burned to CDs or listened to on the computer. The advantages of Podcasts of lectures are that students are able to repeat lectures at their convenience, whether that's while sitting at the computer, exercising, driving or walking on campus, they can review lectures before exams, and that they can listen in on classes they've missed.