Ok, let's see how many here are old enough to do these tasks...
Changing the ribbon on a typewriter.
Checking your beeper.
Using a darkroom (I bet many here can).
Adjusting the rabbit ears on your TV.
Paying with a check inside a retail store.
Using a pay phone.
Calling a radio station to find out what song that was.
Popping in a flash cube.
Taping songs off the radio onto a cassette tape.
Sending a handwritten letter.
Buying from the Fuller Brush Man when he comes to your door.
Manually using the choke on your car.
Cleaning the head of your VCR.
Bringing your film to the drugstore for developing.
Getting out of your chair to change the TV channel.
Loading film into a camera.
Winding your watch.
Reading a print newspaper.
Using a dial-up internet service.
Use a Flip video camera.
Insert a floppy disk into your pc.
Stopping at the gas station to buy a map.
Get full service at a gas station (gas pumped, air & water checked, windshield cleaned).
Boy, have times changed! I confess, I remember how to do all of these (except the darkroom).
Just for fun, any other obsolete task you can think of?