Record players aren’t that hard to fine. Any decent DJ catalog or website will have turntables.
Airships
Steam-powered cars.
Semaphore systems.
As I kid I had a mechanical adding machine that I found endlessly fascinating.
And, of course, Silly String.
The first thing I thought of when I saw the title of this thread was the Pneumatic Telegraph or “tubular post”, which a “find” in this thread shows that other posters have already mentioned.
After I started this thread, I was heartened to find they still have a city-wide pneumatic post in Prague (well at least, it was a going concern in 1999). Ladies and gentlemen, I give you The Potrubni Posti.
Second on Nixie Tubes. (Wow, I thought I was the only one!)
-…Balanced by the 128k Macintosh 
-The Boeing 2707 SST (The “swing-wing” version, only. Preferably in a Pan Am livery)
One more…Steam Tractors.
yes NoClueBoy, homing pigeons are coooo’l. there’s something about the idea of watching your mail fly towards you…
an abacus. it’s still a great way for kids to learn their 123s.
Lay off the seeds, birdbrain!
Phooey, I was going to say Curta Calculator. My brother has one.
Grindstones and forges (my childhome had one of each).
Vaccuum tube transport, manual typewriters, and DOS 3.1.
Dories. With oars.
Model A Fords. My other brother had one (far older than he is).
I’d have included Nixie tubes in my OP if I’d known the name wasn’t “those cool orange neon digital displays I saw around the place when I was a kid”. Even when they were in current use, I thought they were quaint and wonderful. And somehow, in common with much older technology from vinyl records through to valve radios, they were warm, if y’ know what I mean.
you know what Zenster? i think i’ll add rearing homing pigeons to that bbc’s impossible list of things to do… 
Flying boats. Yes, there are 3 that you can get new (Lake, Seawind and the Be-103) but I’m thinking more the luxury Pan-Am clippers
Another vote for dirigibles and pneumatic tubes
Brian
In Dublin there’s a place called the Bad Ass Café (claim to fame is Sinead O’Connor used to waitress there). They’ve got a spring-loaded system where the waiter writes down the order, then puts it in a can above the table and pulls the can against a spring. The can then flies down a cable across the ceiling to the kitchen (or maybe the cashier, I can’t remember). It’s excellent.
Also, the local store by my house in Hong Kong had the best anti-theft device. All the store’s money was kept in a bucket, which was on a string going over pulley, with weight on the other end of the string, and a huge bell attached to the pulley. If you even so much as breathed on the string, the bell rang, and if the bell rang when the shopkeeper wasn’t there, her son would come running out of the back room with a big stick.
You know why I love the dope? It’s where the people who groove on the idea of pneumatic tubes hang out.
I don’t want a city-wide system – but damn, it would be convenient to have one at work…
I thought AUTOMATS were really cool! You walked in, put your coins in a slot, and opened a little door! Take out your sandwich or apple/piece of cake, etc., annd sit down at atable and eat! Really cool 1920’s technology.
Yes, and rotating billboards (you know, the ones that display 2-3 messages by rotating-really cool!
The Nashville Electric Service?
Expl. Abbrv. Pls. ?
I like Console Radios, in their giant, polished wood cabinets.
This is a great LINK to images of two dozen & more Console Radios.
I want to second mycoman’s vote for slide rules. It was the very first thing that popped into my head when I saw the OP title.
My grandmother’s '47 Chevy had windshield wipers powered by a vaccum motor, i.e. the motor that operated the wiper arms used the vacuum from the engine. The major difficulty plaguing the vacuum motor was its inability to maintain a constant wiper blade speed. As the engine vacuum was lowered (when you went up a hill for instance), the wipers would slow down or even stop. Of course, as a kid I thought this was incredibly cool!
I was going to say “amphibious cars”, remembering these:
http://www.amphicars.com/apics1.htm
but check this out
http://www.aquada.co.uk/aquada/homepage.jsp?flash=true
Play the video.
A lot of the stuff mentioned here has evolved so it doesn’t really qualify as “dead end” which brings me to a thought…
Why have certain products stopped evolving? Like sliced bread. Everyone’s still going around touting the wonders of sliced bread and those sob’s are resting on their laurels if you asked me.
They haven’t even tried slicing bread differently at all. They could go with an angle cut which will leave more waste at the ends but give a larger total square inchage for sandwich making. Get moving bread people!
Those people down at the cigarette lighter factory need a little push too. What’s the latest development in cigarette lighters? About fifteen years ago they came out with a little wind blocker thingy that never caught on. Then they gave us the BBQ lighter, which saves us from scorching our epidermis. But that’s it! Can’t these people pursue newer fuel-efficient technologies? Lets stop our dependency on fossil fuels people!