LYNFIELD, Mass. (Sept. 6)—GreenMan Technologies Inc. has signed an agreement with U.S. Century L.L.C. to be the sole producer of roofing shingles from scrap tires for the San Antonio-based company. U.S. Century's patented FlexShake shingles are stamped from the tread of scrap passenger and light truck tires that are coated and granulated to have a "slate" look. GreenMan initially will make the shingles at its California plant. The firm plans to add shingle lines at other facilities, each generating $1 million in revenue annually, according to Bob Davis, GreenMan president and CEO.