Peace Stamps

USA
1977 stamp commemorating 50th anniversary of Peace Bridge, crossing between the United States and Canada.
http://en.wikipedia.org/wiki/Peace_Bridge

India
International Day of Peace September 21, 2005 first day of issue.

Iceland
The Imagine Peace Tower (Icelandic: Friðarsúlan, meaning "the peace column") is a memorial to John Lennon from his widow, Yoko Ono, located on Viðey Island in Kollafjörður Bay near Reykjavík, Iceland. It consists of a tall "tower of light", projected from a white stone monument that has the words "Imagine Peace" carved into it in 24 languages. These words, and the name of the tower, are a reference to Lennon's peace anthem, Imagine.

The Tower consists of 15 searchlights with prisms that act as mirrors, reflecting the column of light vertically into the sky from a 10-metre wide wishing well. It often reaches cloudbase and indeed can be seen penetrating the cloud cover. On a clear night it appears to reach an altitude of at least 4000m. The power for the lights is provided by Iceland's unique geo-thermal energy grid. It uses approximately 75 kW of power.

Buried underneath the light tower are upward of 500,000 written wishes that Ono gathered over the years in another project, called "Wish Trees". Ono plans to have the tower lit every year from 9 October, Lennon's birthday, through 8 December, the date he was shot. Iceland was selected for the project because of its beauty and its eco-friendly use of geothermal energy.

Construction of the tower started on 9 October, 2006 when Ono dedicated the location, and it was officially unveiled on the same date in 2007. The ceremony was broadcast internationally to numerous television networks. In attendance with Ono were son Sean Lennon, bandmate Ringo Starr, and Olivia Harrison, widow of George Harrison, and Olivia's son Dhani Harrison. Paul McCartney was invited, but could not attend due to a court case. Yoko Ono said on the day of the inauguration that the tower was the best thing that she and John had ever done.
http://imaginepeace.com/archives/8263
http://en.wikipedia.org/wiki/Imagine_Peace_Tower

French Andorra

Australia

Canada
1946-47 Peace stamps commemorating the end of WW II and return to peacetime production.

Germany
1961 Europa Common Theme

Cook Islands
http://en.wikipedia.org/wiki/Cook_Islands

Great Britain
Great Britain Peace issue 1946 celebrated end of World War II (right stamp).

Grenada

Italy

Japan
1951 Signing of Peace Treaty

New Zealand
Cover with New Zealand Peace stamps sent to England in 1946.

Poland
Poland 1978 “Peace” by Andre le Brun.

Somalia
2000 Peace in Somalia.
http://en.wikipedia.org/wiki/Somalia

Spain 1997 seeks Peace in its Basque region

Switzerland issued PAX (Peace) stamps to celebrate the end of World War I. Unfortunately, it was not long lasting…and more PAX stamps were issued in 1945 after World War II.