Using satellite images from Google Maps and Google Earth, an Italian computer programmer has stumbled upon the remains of an ancient villa. Luca Mori was studying maps of the region around his town of Sorbolo, near Parma, Italy, when he noticed a prominent oval, shaded form more than 500 meters long. It was the meander of an ancient river, visible because former watercourses absorb different amounts of moisture from the air than their surroundings do.
His eye was caught by unusual 'rectangular shadows' nearby. Curious, he analyzed the image further, and concluded that the lines must represent a buried structure of human origin. Eventually, he traced out what looked like the inner courtyards of a villa.
You can read more at http://www.nature.com/news/2005/050912/full/050912-6.html
OK, if we can use Google Earth to find 2,000-year-old construction, we can assume that it will also find newer construction. I spent some time looking at the location of my great-grandfather's farm but didn't find anything that I recognized as older construction.
Who will be first to make a genealogically-significant find by using Google Earth or other satellite imaging services? If you do, please post a message after this article at http://www.eogn.com to let everyone know.