For your reference, the Washington Post’s map of the shootings at Virginia Tech. Via MetaFilter.
See also Virginia Tech’s campus maps.
Update, 4/17 at 9:30 AM: The Baltimore Sun’s map is a Google Maps mashup. Via Very Spatial.
Update #2, 4/17 at 12:15 PM: The School Violence Resource Center’s map of school shootings and stabbings in the U.S. from 1996 to 2006. Via Catholicgauze.