I recently saw this piece of graffiti in Bristol, and thought I had photographed it, except there was no memory card in my camera. It took me a moment to figure out, but once I did, I thought it totally brilliant. Why can't we all do this? The world would be so much the better for it.
There are examples of it in Prague (on the John Lennon wall), on Bono, as a car bumper sticker, in lights and as a stencil. You can wear it as adornment
or a patch and you can have the T-shirt. You can discover the meaning of the symbols and find variations.
However, I think we should all just do it, especially as the last link suggests.