A participant during the Burning Man 2011 "Rites of Passage" arts and music festival in the Black Rock desert of Nevada, August 31, 2011. More than 50,000 people from all over the world have gathered at the sold out festival which is celebrating its 25th year. [Photo/Agencies]

Participants write personal messages on the wall of "The Temple of Transition" during the Burning Man "Rites of Passage" arts and music festival in the Black Rock desert of Nevada, August 31, 2011. [Photo/Agencies]