Interesting thread. So much amazing stuff today that is so cheap. So many high-tech examples. I just bought an inspection camera for ~ $20 - USB into a laptop, and you have a hi-rez camera the size of a crayon on a cable. I don't know if I will ever use it, but I bought it 'just in case'.
But on the lower tech side, the garage door opener post made me think of this wonder of the ages:
The anti-scald shower valves!
For decades, it was such a pain to take a shower when others were home. If they ran the water, out shower would go cold or hot as the pressure changed. When I re-did the bathrooms, I bought the anti-scald, self-adjusting valves. The mechanism is simplicity itself. It's just a little floating collar inside the valve that responds to pressure variations, and self adjusts to let more water flow on the side with the lower pressure. One moving part, and it works so well, I never feel the slightest change in temperature, no matter how much water is being drawn elsewhere in the house.
A luxury I could afford! It makes the old valves seem like the middle ages.
For simple elegance: garage door opener!
Yes! Our old house had a steep driveway. The routine was to pull in, push the brake pedal, set the parking brake, and only then put it Park (putting it in Park first might jam it up against the downhill pressure). Then get out, raise the garage door, get back in, release the brake, pull in, lower the door.
I put in the garage door opener when DW was pregnant. That was major brownie points, she still mentions it from time to time!
-ERD50