Over 2 million satellite images have been reviewed so far.
Quote from Wired News:
50,000 Volunteers Join Distributed Search for Steve Fossett
Up to 50,000 people are hunting for missing aviator Steve Fossett, in a distributed search using satellite images and Amazon's Mechanical Turk.
The army of online volunteers is scrutinizing satellite images that show small chunks of the 17,000-square-mile region where Fossett's plane is thought to have crashed.
50,000 Volunteers Join Distributed Search for Steve Fossett
