“It was fifty years ago today,” according to the author of The Peace Symbol Turns Fifty. I found more on the famous “nuclear disarmament” mark at Wikipedia (just scroll down a bit), and that’s where I learned this:
    “In Unicode, the peace symbol is U+262E: ☮, and can thus be generated in HTML by typing ☮ or ☮. However, many browsers will not have a font that can display it.”