So, you plug the earphone jack into your favourite audio system, switch it on, and start playing music or whatever. The gubbins inside picks it up, converts it into MP3 format, and stores it in flash memory. When you've recorded all you want, you switch it off, take it out, and later plug the USB jack into your PC. From there, you can retrieve the .mp3 files and do what you want with them.
Something like this would be particularly useful to me because I have many pieces of music on old cassette tapes that I'd like on my iPod. Of course, unscrupulous people may find many pieces of music on my iPod that they'd like on their iPod, but that's another matter...
I wonder if it's possible to buy a decvice like this? Or should I take the fact that the music indistry hasn't entirely collapsed as evidence that no such device is currently available?