Let's say you have some type of audio output device that does not have an audio output jack on it. You want to get the sound from that device in your headphones, computer, tape recorder, etc. Cracking the case to add a jack is out of the question (let's say because it would void warranty, or it's an antique and this would ruin its value, etc. etc., whatever).
What would you do? I'm thinking possibly of an electret mic and preamp, with the mic affixed to the case in front of the speaker. Sounds crude...anything nicer, better, more glorious?