Singer Jason Derulo performs during his Flash Mob with Knicks City Dancers outside of Madison Square Garden on September 28, 2011 in New York City. (Photo by Mike Coppola/Getty Images)

Sheep are waiting in Via Manzoni before the final filming of the Last Shepherd on October 1, 2011 in Milan, Italy. Directed by Marco Bonfanti, L'Ultimo Pastore (The Last Shepherd) tells the story of the life of Renato Zucchelli, the last nomadic shepherd in Milan. (Photo by Pier Marco Tacca/Getty Images)

Leaves are stuck to the road surface on October 5, 2011 in London, England. A combination of late Summer high temperatures and an early fall of leaves onto a sticky non-slip section of road tarmac has created a leafy collage. (Photo by Peter Macdiarmid/Getty Images)

This 1950s photo provided by the Estate of Vivian Maier and John Maloof Collection shows Maier in a self-portrait as she looks into a storefront wearing a hat in New York. New research about Maier shows the enigmatic Chicago nanny was obsessive about honing her skills as a photographer starting in 1950. (Photo by Vivian Maier/Estate of Vivian Maier and John Maloof Collection via AP Photo)

Students take part in a fashion and design entrance examination at Hubei Institute of fine Arts on February 28, 2011 in Wuhan, Hubei Province of China. 202 students took part in the exam and only 24, (10 percent) of them will be enrolled in Hubei Institute of fine Arts. (Photo by ChinaFotoPress/Getty Images). WUHAN, CHINA – FEBRUARY 28

Pope Benedict XVI arrives at the Santa Sabina Basilica for the Ash Wednesday service on March 9, 2011 in Rome, Italy. Ash Wednesday opens the liturgical 40-day period of Lent, a period of prayer, fasting, penitence and alms giving leading up to Easter.

Customers try out the the new iPad2 shortly after it went on sale at the Fifth Avenue Apple store March 11, 2011 in New York City. The iPad 2 became available at 4:00 a.m. Eastern time for online purchase and at 5:00 p.m. today in over 10,000 retail locations.

Rescuers work at the traffic accident site on April 1, 2011 in Xi'an, Shaanxi province of China. A truck collided with a bus at a cross on Friday morning. As the truck headed for the sidewalk, it collided into a pedestrian and 6 vehicles which were stopped nearby. As a result 16 people were injuried, one currently has severe injuries. (Photo by ChinaFotoPress/Getty Images)