Turn Your iPod Into an Old School Cassette Player With a Square Card Reader - Gizmodo

If it works as claimed, here's a fascinating hack for anyone still in love with the analog sound from audio tape. With some simple modifications, Evan Long managed to turn an iPod Touch and a Square credit card reader into a rudimentary cassette player.

The magnetic stripe reader on the Square basically works exactly like the magnetic read and write heads on an old school cassette player or reel-to-reel machine. But to make this work, you'll have to make sure you're using the older version of the Square which doesn't encrypt the data it reads. And to ensure the tape slides easily through the reader, you'll also have to open it up and loosen the read head.

Since the headphone jack on most iPods and the iPhone doubles as a microphone input (that's how the Square reader transfers data) all you then need to do is fire up your favorite audio recording app, and find an easy way to thread the audio tape through. There's a slight chance this might be a completely pointless prank, but the logic and fundamental principles are all in place, and it's simple enough to easily try it yourself. If it doesn't work, it's not like you've destroyed an expensive piece of electronics in the process. [Evan Long via Make]