Hunh. I'm surprised that you would select a fixed medium (CDs) for a variable information source. How often do you plan to press new CDs? Would it not be simpler to use steganography to encode the desired information into GIFs of, say, US weather maps? These maps are revised quite often and it would be natural to send person X a new weather map every day or so. Yes, as we all know from past discussions, it's possible for someone who knows what you're doing to recover the data "hidden" in the pictures. But how likely is that to happen? What's the cost of this (or another non- media-dependent solution) versus the complexity and cost of using CDs as your transport mechanism? [About the CDs: what will the sound like when played on a normal CD player? Isn't this likely to attract attention?] --Alan Wexelblat, Reality Hacker, Author, and Cyberspace Bard Media Lab - Advanced Human Interface Group wex@media.mit.edu Voice: 617-258-9168 Page: 617-945-1842 an53607@anon.penet.fi All the world's a stage and most of us are desperately unrehearsed.