'A Massive Experiment' In Voting On Nov. 2, some 6 million Washington-area voters will use touch-screen machines, a key test of a new technology that will play a major role in deciding what promises to be a very close presidential election. &lt;FONT face="verdana,MS Sans Serif,arial,helvetica" size="-2"\ color="#666666"&gt;&lt;B&gt;-washingtonpost.com&lt;/B&gt;&lt;/FONT&gt;