Google introduced its well-received map services a few months back. The map graphics are clear and allow the user to click and drag the map along great distances. There's also a satellite imaging option that's great fun. It's fun to look up satellite images of your own neighborhood, but you can also take a virtual world tour and spot landmarks near and far.
It was probably inevitable that someone would grab onto the advertising possibilities presented by satellite imaging and the fact that people are actually looking at satellite imaging. MIT Advertising Lab discusses the advertising potential and includes links to a few sites that provide some interesting sights and insights.