What obsolete technology do you still use or would bring back?

[Savonarola]

I would like to return to a time before My Pillow.

That was a glorious era.

Does anyone remember that David Hogg was going to stick it to Mike Lindell and start his own pillow company?  He even wrote a manifesto:

To The Future, Seven days ago they said it could not be done. Seven days ago we joked online about just how powerful a pillow company could be. To the believers - those who dared to imagine a pillow company could be about more than just pillows - thank you for turning our wildest dreams into reality. Rest assured, Good Pillow is well underway :^)

From day one we've set out to create a pillow company that is, simply put: Good. This seemingly straightforward idea stems from the mindset that everyone deserves a Good night's sleep, coupled with the belief that we deserve to feel Good about the brands we choose to support. Good Pillow's commitment to being a quality, ethical, and sustainable company exists at the forefront of all our business decisions large and small. Why? To inspire a new generation of Americans to live the American Dream by giving back and supporting causes you believe in, to create a true conscious consumer movement– all while getting a Good night's sleep. Here's what we mean when we say "Good":

●Good Pillow pledges to support charitable organizations working to improve the lives of everyday Americans & people across the world.

●Good Pillow pledges to have an active dialogue with its customers regarding which causes it will allocate a percentage of profits to.

●Good Pillow pledges to be sustainably sourced and to be environmentally accountable.

●Good Pillow pledges to employ well-paid, unionized manufacturers.

●Good Pillow pledges to be Made in America.● Good Pillow pledges to place a strong emphasis on hiring those who have traditionally struggled with seeking employment, including: veterans, refugees, people with disabilities, and people who were formerly incarcerated.

●Good Pillow pledges to fill our Board of Directors with people who actually​  represent America. We've seen companies and leaders rely on symbolic gestures as a substitute for real change. We commit to ensuring our actions demonstrate the depth of our commitment.

●Good Pillow pledges to appoint a Chief Progressive Officer to its executive team, whose sole purpose is to ensure we stay true to our vision.

We'll be honest - this isn't going to happen overnight, and that's because we're committed to doing this the right way. Though we've spent ⅓ of our lives on pillows, we can't say we know everything about pillow manufacturing. That's why we're not sacrificing quality for time. We must invest in our foundation to make Good on our promises.

At present, Good Pillow is in the midst of negotiating and solidifying key details with our Board of Directors, manufacturing partners, employees, advisors, and an exciting influencer network with a combined reach of over 250 million people and counting. Before we launch, though, we must take some time to put our heads down, out of respect for the three year anniversary of the shooting in Parkland, Florida on February 14th. While we step back to honor those we lost on that horrific day, we remain fully committed to delivering on what we've promised.

We couldn't be more thrilled to share more important updates immediately following our blackout period. Thank you for embarking on this journey with us to prove that we can turn Good dreams into reality : ) ~ David & Will

Now, with such a solid business plan, you would think there's no way he could have failed and that by today whole rivers of gold would be flowing into his hands.  Tragically he made a textbook mistake, he didn't write his manifesto in Courier Font; (my version is an improvement.)  Consequently he left the company after two months and bad pillows continue to dominate the market.   

[Savonarola]

That's funny Sav - I still have my old scientific calculator that goes back to at least my undergrad BSc days, if not to high school.

I'm embarrassed to admit I've completely forgotten all the higher level functions it can do, but it still works to do addition / subtraction.  It's still on my desk at work and I still use it.  It's not a fancy graphing calculator like your HP-48 but 25+ years old it still works.

What brand?

Did anyone ever use the hyperbolic functions that many scientific calculators have (sinh, cosh and tanh)?  I'm curious what sort of discipline would use that.  (I know a hanging cable is a hyperbola so maybe architecture or civil engineering? )

[viper37]

So do you have an obsolete technology that you still use;

paper, at work. 

[11B4V]

Pencil

[Eddie Teach]

So do you have an obsolete technology that you still use;

paper, at work. 

Paper won't be obsolete as long as electrical power can fail.

[mongers]

Pencil

This.

I still occasionally use them, I vividly remember the orange/yellow oval one with the softer 'lead' that my old man used when he was doing building work/chippying. 

[Syt]

I've been thinking about this on and off the last few days, and I have to admit I can't really think of something to bring back except for nostalgia's sake.

I'm personally somewhat surprised how quickly some consumer electronics have come and gone. As a kid, portable cassette players were just becoming common (early 80s). Besides music tapes, audio plays for kids were super popular. But I wouldn't want to go to the hassle of rewinding tapes, fixing messed up, unspooled tapes with a pencil, or the slow death of batteries heralded by increasingly slurred playback. (I did enjoy recording my own audio plays or "radio shows" as a kid, though.) My favorite player would automatically switch playback sides at the end of a tape and had a built in AM/FM radio.

Then the portable disc player - better, but oh so prone to skips if you moved, like, at all. Next up was a disc player that could read data disks that you filled with MP3s. Yay!

Then the MP3 players. I had a few - a cheap Chinese one with 120 or so MB, about the size of a cigarette lighter, then an Archos brick that stored tons of MP3s, and had an LCD screen to watch videos (but the battery life was garbage, and it was picky about video formats), and finally an iPod with 150 GB (GB? is that right?) which I disliked, because most of my MP3s weren't properly tagged as iTunes would want them to, leading to my neatly arranged folders turning into an unmanageable mess, and the player died a little after 2 years of use.

Since then my phone has been my portable media device, not least thanks to Spotify that keeps me going with pretty much anything I need in music and podcasts. The last change I made was moving to wireless headphones which I was long reluctant to do, but my Sennheisers are quite nice. (But they suck for making calls.)

[celedhring]

I was about to say vinyl, but that's already happening right? Nowadays the vinyl section at my local entertainment store is larger than the CD section (note: neither is very large). I always loved my mom's vinyl collection, with those large covers and luxurious album art. CDs were so tiny in comparison, even if more practical. And with digital you don't have even that.

[Duque de Bragança]

I still have old consoles (modified for playing imports and 60 Hz mainly), from the 16-bit era to the PS3 (retro now). No CRT unfortunately, too bulky and I lack space, but I also a Japanese device for scan lines on a flat screen for the retro experience.

I had a AM/FM/SW radio CD-cassette player (recently disposed of), then a portable CD player, but even the anti-skip system would end up scratching the CDs in time.

Switched to iPod, but following Mac OS X evolutions I could no longer transfer music from my Mac, so all through my smart phone now.

I am still using physical media though I would not call blu-ray and 4K blu-ray obsolete technology.  Maybe DVD? 
Some HD audio formats such as DVD-Audio or SACD, could be termed as obsolete with little to no new releases (DVD-Audio).
Surviving in classical music but not really elsewhere, with some jazz perhaps and classic rock.

I still use Roman numerals in writing, with a pencil.