VerySpatial.com reported about the release of full Landsat data libraries available in the USGS. Now you can access over the past 35 years of Landsat 1 through Landsat 7. To access these data can be through the USGS Global Visualization Viewer (GloVis) or from EarthExplorer. In addition the USGS itself has made remote sensing class projects so much easier for users.