Here's a short list of things I remember well, but which my kids either don't remember at all, or consider quaint and curious.
Television sets without remote controls: back in the day, we got up to change the channel on the television set. There was no channel surfing during the commercials. And some people ended up watching the same channel all night because nobody wanted to get up.
Party lines: I can't decide if the world is a better place without these, or not. There was so much drama around party lines - sneaking the phone off the cradle and listening in; having conversations interrupted by a crabby neighbor telling us to get off the phone; stopping to chat with your fellow party-liner.
Individual ring tones: I'm not talking Beethoven's Fifth. I'm talking two longs and a short for your house, three shorts for your neighbors', and two shorts and a long for the guy around the corner. Everybody's phone rang every time, and you answered only your ring.
Phones with cords: everybody had a phone table when I was kid, and that's where you sat to talk. Private conversation? Puh-leese - you shouldn't be saying anything you wouldn't say with your mother in the room, anyway.
Phones with rotary dials: I still love the sound and feel of a rotary dial. Each number sounds different because the dial travels a different distance for each number. I remember a movie where a mystery was solved by someone hearing the sound of a number being dialed and later messing around with the rotary dial until they figured out what the number was.
Metal tv stands with wheels: these were flimsy little things which enabled you to roll the tv into the dining room if there was something special on. Of course, this implies that a) tvs were a lot smaller (and they were! Seventeen inches was considered a reasonable size!) and b) you didn't have to worry about plugging the thing into cable. You used your rabbit ears.
Milk boxes: on the porch. For the delivery of milk in bottles with foil caps. The cream floated just under the cap.
Pedal-operated sewing machines: I really liked sewing on these. Your ability to control the speed of the machine was nearly infinite, limited only by how fast you could pedal.
Push mowers: I saw a guy mowing his lawn with one of these the other day. I thought, Gosh. He should take better care of his antiques.
Metal garbage cans: I'm sure people still use these somewhere, but in my town it's all big plastic bins provided by the waste removal company. I kinda miss those gun-metal gray cans, with their dents and their lids that didn't fit after the first year or so. Those cans took a lot of punishment - and it showed.
Cranks for rolling car windows up: it's all buttons now.
Typewriters: I still have the little green portable I took away to college with me, but the ribbons are a thing of the past.
Slide rules: yes, I minored in math and I did not own a calculator. When I was in college, a four-function calculator was still a prohibitively-expensive item; I settled for the slide rule and the books of math tables.
Blackboards: and erasers and chalk dust. Last year we got a SmartBoard in the classroom where I tutor - we can now display pages from the computer, or let the kids 'write' on the board and save their writing to a file, or scan text-book pages and display them. No more teachers' pets staying after school to clean the erasers.
Bench seats in cars: three in the front, and three (or four) in the back. We used to wage battles for the front seat and the windows. And some poor schmuck (or, in our family two poor schmucks) had to sit in the middle of the back with no view and no air.
Recess: this was the most important part of the school day when I was a kid. It's when all the socializing happened; when relationships formed or fizzled; when dominance issues were resolved. Now recess in 'structured.' Yikes.