Beyond his well-documented contributions to the musical canon, in life and death, John Lennon remains a symbol of peace. It is apt then that a selection of some of his greatest songs are the basis for Instant Karma: The Campaign to Save Darfur, a compilation of covers by everyone from Green Day and U2 to Flaming Lips and Postal Service. Due June 12, the set will support Amnesty International's campaign to focus attention and mobilize activism around the crisis in the Sudan: genocide at the hands of the Janjaweed militias -- bands of fighters backed by the Sudanese government -- a campaign of violence that began in February 2003.