Stay a photographer long enough and unless you exercise exceptional discipline you'll eventually end up with a closet or drawer full of items that still perform the function for which they were designed but have been rendered unnecessary or obsolete by the march of technology. I have my share of them, some of which you see in the photo above. For the benefit of you too young to remember, here's a rundown of the highlights.
Handheld exposure meter -- I consider this a borderline anachronism. It's not something I'd carry with me when I'm shooting digital photos in continuous light. Auto-exposure and instant image review with color histograms are hard to beat. On the other hand, an incident flash meter sure comes in handy when I'm doing studio or location lighting, especially when I want to take the guesswork out of setting or measuring lighting ratios. In the unlikely event that some cretin were to steal this I'd had to replace it. Lucky for me that similar models are still for sale.
Loupe -- Back in the old days we used to use a 4X or 8X loupe to examine our color transparencies on a light table--another anachronism. It was the old-school equivalent of pixel-peeping. I still have hundreds of transparencies, so the loupe and light table still come in handy from time to time. That said, if they were to disappear I might not notice for months and I doubt I'd replace them once I did notice.
Color contrast and correction filters -- If you shoot actual black and white film rather than converting color to B&W, you often run into situations where two very different colors--red and green for example--translate in almost identical shades of gray. The solution was to use a filter that would cause one color or the other to appear darker or lighter than it would without the filter. These days you just convert a color image to grayscale but save the color information, adjust a view sliders for the colors you want to lighten or darken, and you're good to go. As for the color correction filters, auto white balance has rendered them quaint. My polarizing and neutral density filters are still quite handy; the rest, not so much.
Non-TTL hotshoe flash unit -- I'm well aware that those of the Strobist faith love hooking these things up to radio triggers that cost more than the flash itself is worth and using the combination to create elaborate lighting set-ups. The rest of us find it hard to embrace 30 year-old technology that often requires the use of a flash meter (see above), PC cords or flash triggers, and that can have enough voltage to fry the digital circuits in our camera. I gave away my old-faithful Vivitar 283 long ago and don't miss it.
I could go on. There's the Minox "spy camera" my grandfather gave me 40 years ago, the Premier print dryer I used to dry fiber-based prints, the reverse-adapters for my manual focus lenses... you get the idea.
And now it's your turn. Other than film cameras (come on, you can do better than that) what do you keep around that you used to use faithfully, barely have any use for now, and still can't find the heart to throw away? You digital shooters may be chagrined to discover that this list constitutes a lot more of your equipment than you'd like to admit. If so, that's okay. We're all friends here and we all feel your pain.