CAIRO, EGYPT - FEBRUARY 11:  Anti-government demonstrators celebrate in Tahrir Square upon hearing the news of the resignation of Egyptian President Hosni Mubarak on February 11, 2011 in Cairo, Egypt. After 18 days of widespread protests, Egyptian President Hosni Mubarak, who has now left Cairo for his home in the Egyptian resort town of Sharm el-Sheik, announced that he would step down.  (Photo by John Moore/Getty Images)