A Friend in the Desert
Located in Huara, Tarapaca, Chile, this friendly giant was made by friendly artists to greet those above them. Seriously, this guy was made to be seen on the Google Earth Satellite. It's one of Google Earth's highlighted locations, so if you poke around the mountains in Chile, you're bound to find it eventually.
The Huge Target
No, the zodiac killer did not make this target on the ground, but that would have been a good guess. Instead, this was also a creation by the briliant folks behind Burning Man. If you want to see what all the fuss is about, go to these coordinates 37.563936, -116.85123.