Duck & Cover!
In my office earlier I learned that a 23-yr old coworker of mine had no real memories of the Cold War and he didn't believe me when I mentioned teachers referring to the local tornado test sirens as the nuclear bomb alerts. I remember being told specifically that the safety precautions at school were the same for a tornado as they would be for a nuclear bomb. While we were never shown "Duck & Cover", it was certainly described to us as a safety precaution for emergencies.
In the spirit of this conversation, here's Duck & Cover:
http://www.youtube.com/watch?v=C0K_LZDXp0I
...and, yes, I realize that this gives my LiveJournal two straight Cold-War-related posts. That's what I do.