My Christmas present: my sister got me an old-school stereo-scope with about 300 cards-- mostly scenery and travel shots from all over. This is so freakin’ cool. I am so easily amused. I love the old scenery and also the people who pose with it.I think "This little boy running in front of the tram here in Munich. . . he’d be like 90 now.
Just had to share. I love this old optical stuff. I need to get her to get me a magic lantern next Christmas. . .
Woo. Absolutely cool gift! I’m envious. 
I have one too! Bought it years ago and have collected cards off and on, from a variety of collections and series. I have a lot of black and white pictures, but even more tinted color ones.
Do your cards have information printed on the back, about the pictures?
Cool! I found a few modern reproductions of old cards like that, with cheap stereoscopic lenses built in, at tourists shops.
I now keep them with my collection of 3-D-cards that come with the silly red-and-green plastic glasses. 