ELDORET, Kenya) — U.S. presidential candidate Barack Obama phoned Kenya's opposition leader as diplomatic attempts to end Kenya's political crisis intensified Tuesday. The death toll from a week of violence after President Mwai Kibaki's disputed re-election has reached nearly 500, according to the government, though the opposition claimed the death toll could be up to 1,000. On Monday, Kibaki and opposition leader Raila Odinga made key concessions under U.S. pressure. Obama — a Democratic Party candidate who is of Kenyan descent — called Odinga late Monday or early Tuesday, said Odinga's spokesman, Salim Lone. "He called to express grave concern...