Dial up modems.
I've still got one somewhere, and Lt. Col. Larrington (retd.) still connects to teh Intarwebs with one, though I think he may be considering the acquisition of broadbean.
Cassette tapes (although I understand that the only people who still use 'em in any quantity now are the polis)
You can still buy 'em in my local Sainsbury's.
Soda Stream machines
We still use soda streams (and bought a new one only last year)!
Lt. Col. Larrington (retd.) got a new one this summer...
Draft excluding snakes
Got one of them. Well, technically it's a lizard.
Is quadrophonic sound still around?
Sort of, only now people with four ears call it "Dolby 5.1"