I abidingly loved my Viewmaster when I was a kid. If you’re not sure what one is, I feel badly for you, but it’s the descendent of those old stereoscopic photo viewers, evolved over a century to become a brilliant children’s toy. My favorite slides were the Hanna-Barbera character tie-ins, which, looking back, were of VASTLY higher quality than the cheaply ground-out cartoons themselves. I also quite loved the travelogues - I may never have been to the Alps, but by god, I saw them in full 3D glory when I was five! I’d love to wax rhapsodic at length about these things, but DM’s Paul J. Gallagher beat me to the post by about a year. It’s a wonderful post, you should have a look.
In this Viewmaster ad from 1971, Jodie Foster, a full five years before her show-stealing performance as an underaged prostitute in Taxi Driver brought her to America and John Hinkley Jr.’s attention, similarly (though far less scandalously) stole the show from the venerable Henry Fonda!