An older patron called late morning one day, and asked if we had a slide projector. Before I could answer (and the answer would have been "no"), she continued, saying that she had a bunch of slides from different places she's been - she hadn't looked at them for years, and just wanted to see what was on them.
While she was talking, and knowing we didn't have a slide projector, I started thinking of other options to accommodate her. To view slides, all you need to do is project light through them, so I thought maybe using a digital projector and holding the slide in front of it might work. Or even just a flashlight.
Then for some reason I thought of our microfilm machine. I've never tried it with slides, but it seemed like it would work - just put the slide on the glass where the film/fiche would go, and it should be nicely viewable on the screen.
So I told the patron to come in, and that we could find something she could use. If the microfilm machine didn't work, there's always a flashlight.
About mid-afternoon she arrived, with a shopping bag full of slide boxes. We went over to the microfilm machine, and I showed her how to turn it on and put a slide on the glass - and amazingly, it worked great:
She's not a very techie person, but she could easily handle swapping out slides and aligning them so she could see them on the screen. There was hardly anything to it, and the image was nice and big. And, a side benefit was that she could even print them!
She spent a couple hours looking at them - not rushed at all, just enjoying them. She let me know when she was leaving so I could turn "that machine" off, and she seemed quite happy. Yay! And double-yay for successfully improvising.
Also: an interesting aside to this reference question is that I believe this is the first time I've ever seen a color image on our microfilm machine - I never knew it had it in it.