I ran across a cool Windows program the other day: NASA World Wind. It's an application that allows you to view landsat and shuttle radar topography data from any view on earth. What's doubly cool is that it has high resolution photography of urban centers throughout the US, at considerably beter resolution than the imagery available via Google Maps. For instance, check out this image of Pixar via WorldWind and compare it to this Google Maps view of Pixar. Quite a big difference.
It's a fairly big download (180 megabytes) but very cool. Try it out.