You and I, Frank, are of the same generation when this meant more than just pissing off a national guardsman. It meant different things to different people: for some it was to end the war in Viet Nam, for others a wish for peace despite our wearing a uniform. It was a symbol of identification among same-thing individuals, and also a call for civil rights for all people, regardless of color, age, or gender. It was heavily used by our generation when we were young but I rarely see it today... I hope that doesn't mean we've given up.
If you've ever wanted to make a difference but found it hard to believe that one person could... check out the Kiva Team Caedes discussion thread and discover that anything is possible.
-Nik