This is the smaller version, and the larger version - which is 2400x1200, just HUGE - is
HERE.
That image is also 486k in size and will take forever to display on most people's connections. But when it does... well damn!
This is a NASA image if I recall, made by putting together tons of nighttime satellite images. It's also available as a wall poster.
Check out the Nile, little dots in Greenland and a big spot in N. Alaska.