… or are you just sending me a ringtone?
Union organizers, Egyptians and paranoids listen up because XDA’s Fredly has cooked up StegDroid just for you. By means of steganography, and he’s doing his dissertation on it so you know this app is high-grade primo academic shit, you may type your top secret message, then record any audio you want for a dozen seconds, then shoot that ogg (common audio format like wav) to anyone with this program who upon opening it will see the message, though were anyone else to intercept it, if it fell into the wrong hands, it would play like any other sound file.
And if you’re concerned that those wrong hands may also have a copy of StegDroid or you are a known steganographer, you may encrypt your messages and in addition to that if you check of Paranoid Mode the program will eliminate all cached data including your encryption key upon closing or minimizing the program.
It’s in its alpha stages but hey, neat trick, so you might as well hit up the market and grab a copy of StegDroid, then if you have any questions or tips or a pat on the ass to give the developer, hit the XDA thread.