Palestinian youths walk during a protest marking the Nakba....

Palestinian youths walk during a protest marking the Nakba (The Day of catastrophe), on the edge of East Jerusalem May 12, 2007. REUTERS/Mahfouz Abu Turk (JERUSALEM)

A Palestinian boy holds up a symbolic key during protest marking the Nakba (The Day of catastrophe), on the edge of East Jerusalem May 12, 2007. REUTERS/Mahfouz Abu Turk (JERUSALEM)

A Palestinian boy scout holds a representation of a key during a rally marking 'the Naqba,' or 'catastrophe', the term Palestinians use to describe Israel's creation on May 15, 1948, in the West Bank city of Ramallah, Friday, May 11, 2007. Some 700,000 Palestinians fled or were driven from their homes during the war that followed the declaration of the Jewish state. (AP Photo/Nasser Shiyoukhi)

A Palestinian boy (C) holds up a symbolic key , marking the Nakba (The Day of catastrophe), in the West Bank city of Ramallah May 11, 2007. REUTERS/Loay Abu Haykel (WEST BANK)

A Palestinian boy holds up a symbolic key , marking the Nakba (The Day of catastrophe), in the West Bank city of Ramallah May 11, 2007. REUTERS/Loay Abu Haykel (WEST BANK)

Palestinians stand in front of Israeli soldiers as they protest against Israel's separation barrier in the village of Umm Salamona, near the West Bank town of Bethlehem, Friday, May 11, 2007. Israel says the barrier is necessary for security while Palestinians call it a land grab. (AP Photo/Oded Balilty)