The Peace Symbol is a very well known symbol of peace all over the world. The symbol itself is simple, a circle with a line down the middle, and two diagonal lines from the bottom meeting the center line a little bit below the midpoint of the vertical line. Or, better yet, a Mercedes logo with the middle line going all the way through. I am sure that at least 99% of the people who are reading this know what a peace symbol looks like.
The history of the peace symbol is somewhat murky, it begin life sometime in the late 50's as an anti-nuclear weapon symbol. Where exactly the activists got the symbol from is unknown.
One theory is that it represents a cross with the arms broken off, in other words, an anti-Christian symbol. I don't see any reason to believe this theory at all.
Another theory is that it is the Norse rune for war stood upside down.
Whatever the origin of the symbol, it became more popular in the 60's, and was associated with the movement to end the Vietnam War. Displaying the peace symbol quickly turned into somewhat of a fashion statement, with hippies and the ilk painting it on their body in day glo symbol, (or at least that is the cliche...after all, if you remember the 60's, you weren't there). After the war ended, probably due to reasons unrelated to people painting themselves, the peace symbol continued to be popular, but more as a cool piece of graffiti to scrawl on things then as a serious political statement.
And to this day, that is about where the peace symbol sticks in our national consciousness.