It was recently reported that someone inadvertently discovered the remains of an ancient Roman villa using satellite imagery from Google Maps. The image which led to the finding is located here. The discoloured oval shape is very clearly visible. It doesn't look much like a villa to me, and frankly I can't see for the life of me how someone would recognise such a vague discolouration as being an archaeological site. They must have a very keen eye indeed. I wonder how many people are now spending hours scanning through Google Maps to try and find similar sites.