Remember, whenever you're making a holograph device from household twice, measure twice, break once.

If you were technologically active in ye olde 1990s or 2000s, you probably have some old CD cases lying around. Or small, clear DVD cases. Well, well now you* can make a hologram machine from their clear covers that people are already making videos for on YouTube (I didn't check if... other sites had the technology yet). They're technically called jewel cases, and they're informally called "old stuff you should really back up" or "empty discs you'll never use." As it happens, though, if you can actually make a working hologram device out of a carefully-cut CD case and a smartphone that play videos. Or you can wait six months for a company that sees this video to make the newest iPhone accessory people make you feel bad for not owning.

Sources: Mrwhosetheboss