I saw this in a Punk-fan-zine, Just passing on the idea.
Step 1: Un screw..
Unscrew the five screws and open the cassette carefully so you don't
loose any parts.
Step 2: Unwind
Unwind the reels, measure and cut the desired section of the tape.
mine measures about 8 11/16ths in inches.
Step 3: Tape
with masking tape, tape the two ends flush with eachother. Make sure that you tape the back side only.
Step 4: Place it
Place it back on one of the reels (see red pattern). Screw the cassette back together.
Place it into a tape deck and enjoy. You can also record over what is currently there.
I think you get about 6 seconds of running time.
So go anoy your family or use it to learn that one guitar lick in that one song that you like so much.