Tiny Sensors That  Can Track Anything They're small, smart and vigilant, the sort of miniature technology that science fiction writers once dreamed of. But the battery-powered, wireless sensors sometimes known as "smart dust" are here, and they're making their way into the electronic fabric of our lives. &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;