I still have a big paper bag of cassettes - but not cassette player to check whats on some of them. I been thinking of getting a walkman on ebay, just be able to transfer them to mp3, and store them.
We use to record demo's on cassette karaoke machines... using head phones as a mic. Little known fact, you can plug a headphone in the mic input and use as a mic - least the older ones. haha