Call a friend, just to shoot the breeze and catch up. Record the conversation. Make sure to tell your friend what you are doing, but be kind of vague about why you are doing it. Say it’s a personal audio journal that you’re working on, then quickly change the subject. (If your friend is likely to end up in court or face an independent prosecutor, pick a different friend to record. If something incriminating is said, destroy the tape.)
After the conversation is over, label the tape, with a first name and date. Then, put the tape in a secure place where it won’t be lost forever, but won’t be found for years.
When you come across the tape in a few years, during a move or something like that, give the tape to your friend. Once he hears it, he’ll say something like, “I can’t believe I sound like that on tape,” or “I hate the way I sound on tape.” But he’ll really be shocked at the things he was saying, all those years ago.