Not to change the subject (again) but I always thought one of the most fascinating machines of all time was the modern printing press (modern as in circa 1950). I used to stand outside the windows of the local newspaper printing room and watch them crank out a newspaper (which I then delivered). To this day I have never figured out how anyone designed a machine that could take raw rolls of newsprint and create a ready-to-read paper out of it in one fell swoop. And the rumble and the roar sounded more like a train than anything else. .
Working late on the copy desk, my final duty most nights was checking the first copies of the paper as they came off the press, which meant I was right there when that big train started to roll. A lasting childhood memory is being taken to the Boston Globe by my dad for my 11th or 12th birthday, going on the guided tour and asking so many questions that the tour guide finally asked me to push the button that would start that afternoon's press run! I was thrilled beyond belief and even got a linotype slug as a souvenir. I loved listening to the radio as a kid and still do, but I was writing a neighborhood newspaper as well, and I knew I'd get into one of those fields as a grown-up by the time I was 10.