1 pointBack in college, I remember the machines that punched the cards collected all the little punch-outs in a waste basket inside the cabinet. We called them "beta particles". If you dumped a bunch of beta particles in somebody's car, there wasn't a vacuum cleaner made that could get them all out. Or so I've heard.
1 pointI used used punch cards as book marks until the Amazon Kindle came out... They are also quite useful for ad-hoc length markers: mark any appropriate length you want and use it where metal rulers are either too big or aren't allowed. When going out to sea and measuring printed fathometer outputs, we used a ten-spacer to mark up punch cards that could be put onto the electrostatically burned paper and read depths down to 2 fathoms accuracy.