LAGUNA NIGUEL, Calif. - Clark Foam, which held a virtual monopoly on the manufacture of blank forms used to create the world's surfboards, has closed its doors because it has violated pollution and safety regulations and would need millions of dollars to comply in the future, its owner said. The company, a pioneer in the design and production of polyester boards, announced Monday that it was closing immediately. That left surf shops and board manufacturers scrambling. "They've been the lifeblood of the surfboard manufacturing business for 40 years" and produced perhaps 90 percent of the polyester foam blanks, said Chris...