When I was young I read all the books written by Douglas Adams. I liked it so much that I have managed to persuade my parents to buy the audio books of the titles I have read. I remember getting larges boxes with up to twenty audio cassettes for each book and listening to one cassette each night. Today one can get audio books in 3 different methods – audio books on cassettes, audio books on CDs and audio books on MP3 or other media files. In this article I will examine the pros and cons of each audio book method. 1. Audio books on cassettes are the oldest method. Their quality is moderate. However, their quality maintains stable for long periods. Each cassette usually contains one or two chapters of the audio book. Most of the listeners find it inconvenient to change the cassettes so frequently. However, some find it easy having a cassette for each chapter. The main disadvantage of audio books on cassettes is the fact that audio book on cassettes weight more than the old fashioned book and occupies more space. It is definitely less convenient. Furthermore, it costs more than the same title on all other methods – the old fashioned book, audio book on a CD or on an MP3 file. 2. Audio books on CDs exist in the market for more than 10 years. However, this method is not as popular as one think it should be. Although it is cheaper and far more convenient than audio books on cassettes it is still as common as audio books on cassettes used to be. Some tend to ascribe this phenomenon to the mass return to the old fashioned books in the past few years. 3. Audio books on MP3 or other media files have many advantages – they are much cheaper than the other audio books’ methods, they occupy no physical space at all and their quality is good. Their popularity increased enormously in the past year, but they are still less popular than the other audio books’ methods. It is estimated that the popularity of MP3 mobile players as IPod will initiate a revolution considering audio books.