A sign marks Mexico's border with the United States as lanes are closed at the San Ysidro port of entry in Tijuana, Mexico, on Saturday, April 17, 2010. (Associated Press)

Photo by: Guillermo Arias

A sign marks Mexico's border with the United States as lanes are closed at the San Ysidro port of entry in Tijuana, Mexico, on Saturday, April 17, 2010. (Associated Press)