My Orizuru Paper Crane for Hiroshima - May there be Peace.
"Orizuru - the paper crane - is the symbol of peace.
[...]Do it on August 6th in dedication to the Victims of the Bomb, repeating to yourself and to the world NO MORE HIROSHIMA as you do it.
Then the folding of the paper crane, you will realize will become a meditation you share with the world.
You can bury the orizuru you made in your back yard, hang it in your room, keep it inside a book you love to read, or send it to a friend."
- Yoko Ono (link)