Looking back at old visions of the future, they always seem to imagine the obvious things, e.g. flying cars and nuclear power. What I haven't ever seen is anything close to modern computers, which arguably have just as profound an impact on our lives and are probably more impressive technologically.
Another well known phenomenon in old science fiction is the utter lack mobile phones. Flying around space, shooting at each other with laser rifles. And then they hop into a phone booth to have A VIDEO CALL! (Yes, I'm looking at you, Blade Runner.)
(And before anybody mentions Star Trek - Those were actually more like small and fancy Walkie-Talkies. Deal with it.)
