If you enjoy the Google Maps feature, you might want to download the NASA World Wind software. It lets you zoom in anywhere in the world, with different overlays to choose from. Urban areas have super high-res 0.1 meter resolution available. A cool thing about World Wind is that you can view the scenery from different angles, it shows the relief of the terrain in 3D. It does this by taking the flat photo data and combining with the USGS topographic info, to stretch the photos and render them 3D. It's definitely software that makes you want a higher-horsepower computer.