We are planning to use the BookPort to listen to RFB&D digital audio files. We are told that we must first buy a key for $10 from RFB&D; I believe the key comes on a floppy disk. We are going to use a 1 gigabyte card in the BookPort. If anyone has experience using this key and using the Bookport for RFB&D books, I would like to hear about that. Thanks, Janice Sowokinos