Argentinian President Nestor Kirchner, Bolivian President Evo Morales, Brazilian President Luiz Inacio Lula da Silva and Venezuelan President Hugo Chavez (from L to R) pose for photo in Argentinian city of Puerto Iguazu, May 4, 2006.(Xinhua/Reuters Photo)

Argentinian President Nestor Kirchner, Bolivian President Evo Morales, Brazilian President Luiz Inacio Lula da Silva and Venezuelan President Hugo Chavez (from L to R) pose for photo in Argentinian city of Puerto Iguazu, May 4, 2006.(Xinhua/Reuters Photo)