While bored working on my placement year at Uni a lad in the next office of the company I was posted at (who did ninjutsu) told me you could make ninja stars from CDs. This was 1998 and writing CDs was full of peril and many a coaster was produced when the CD wouldn't close its session correctly.
Anyway I marked out a few ninja star designs and cut them out with scissors. I was in the office on my own this day and so once cut out I decided to take them for a spin...excuse the pun. I was absolutely amazed how well they flew and was hurling the, up and down the office. Crawling under a desk to retrieve one I popped my head back up to find a senior manager standing in in the door grinning. I have no idea if he had been watching me, but I did my best to pretend to have been sorting out some cables. It was never mentioned and I'd like to think he went on to make his own ninja stars.
So don't bin them, make ninja stars, the original office fidget spinners in the days before PC culture and health and safety.