Audible.com today announced that it will release a Mac compatible version of the company’s Otis portable digital audio player this Friday, December 6. The device allows users to download audio files, transfer them to the Otis and listen to any of Audible’s 34,000 hours of spoken audio. The Audible.com Otis, with 64 MB of internal memory and a card slot for adding an external SD memory card, is capable of playing MP3 files as well as Audible’s own secure audio formats. The Audible.com Otis is available for free when the user joins one of the company’s flat-rate AudibleListener membership programs for 12 months.