I have to agree with Brandon Keim, who reviewed this map for Wired Magazine (here): it most definitely is one of “the coolest planetary maps ever”.
This map is of the dark side of the moon, which here looks more like a Jackson Pollock action painting, its riotous colours corresponding to geological materials and phenomena. Many of the colour spots are circular in nature, reflecting the large number of meteorites that have impacted on the lunar surface, unprotected by an atmosphere, over many, many centuries.
The map is one of a series produced by NASA and the US Geological Survey between 1971 and 1998. “If you’re on a public or work computer that’s set to a generic desktop background, download some and spread the wonder,” Keim suggests. Hear, hear!
This map was suggested by Max Kahn. The original article (cf. sup.) also contains links to further maps of the Moon, Mercury, Mars, Venus and three moons of Jupiter (Io, Ganymede and Callisto).