EarthSight is a free viewer application using NASA satellite imagery to show Earth from virtual orbit.
Image credits: NASA, Earth Observatory team
You can 'zoom in' to a 2x2 km resolution (1 pixel == 2x2 km) for any place on this planet.
This application is self-contained, it does not need any connection to the internet
Prerequisites: 256 MByte memory, Pentium/Athlon (Win32/Linux) or G3/G4 (MacOSX) processor
Have fun discovering our home planet. You can find more photorealistic Earth images here.