Seems like it is for real and a very good idea, each user is presented with one image to review. All using something called amazon mechanical turk, no doubt something a stack of balloonists are about to learn about.
More upto date images for google earth http://s3.amazonaws.com/fossett/geoeye-color.kml
Happy hunting, would be amazing if this overtook the work of several aircraft and high tech equipment.
Spread the word amongst your ballooning friends.