This insanely clever ring was designed by Luke Jerram and jeweler Tamrakar for Jerram's wedding. Featuring a built in lens and a transparent slide with an image of him and bride-to-be Shelina Nanji, it turns into a projector when a light is shined through it.
The ring is updatable, too, with the ability to swap out the slides built right in. It's a pretty brilliant idea, one that is unfortunately a one-of-a-kind object. When asked to make one for other couples (which happens all the time, predictably), he responds with this: "Congratulations on your engagement! I'm afraid this ring was a one off, made for my wife. I'm afraid you'll have to make your own unique ring for your own unique partner!"