IBM Claims Computer Speed Title IBM Corp. plans to announce Wednesday that it has built the world's fastest supercomputer at one of its facilities in Rochester, Minn., wresting the title from a system in Japan.&lt;BR&gt;\&lt;FONT face="verdana,MS Sans Serif,arial,helvetica" size="-2"\ color="#666666"&gt;&lt;B&gt;-The Washington Post&lt;/B&gt;&lt;/FONT&gt;