Israel's Prime Minister Ehud Olmert hosts Israeli scientists at his sukkah, a traditional hut, in Jerusalem October 15, 2008. A sukkah is a ritual hut used during the week-long Jewish holiday of Sukkot which began Monday. Observant Jews build these temporary structures to commemorate the lifestyle of the biblical Hebrews during the exodus from Egypt led by Moses more than 3,000 years ago. REUTERS/Sebastian Scheiner/Pool (JERUSALEM)