It does not happen very often that something of great value is made available free of charge, and in large quantities. Courtesy of US Government and GeoEye, you can now access some 180,000 scenes, one meter resolution (black and white) and four meter resolution (multi-spectral), captured by OrbView-3 satellite around the world between 2003 and 2007. The initial data format available is GeoEye's Basic Enhanced (L1B) product.
The OrbView-3 dataset is amongst 170 collections of aerial photography and remotely sensed data catalogued in the National Satellite Land Remote Sensing Data Archive and made available for download (mostly at no cost) via USGS EarthExplorer.
As spotted on spatialsource.com.au