GISUser has a press release about NASA’s Blue Marble, a 1 km resolution image of the world created from its Terra satellite’s Moderate Resolution Imaging Spectroradiometer or MODIS. MODIS is also a great source for remote snesing images of current natural events (e.g. hurricanes, floodings, forest fires, etc.) Some sample images are available at Earth Observatory and files are available for download on its FTP site. Don’t expect to be able to get any in the near future as it already has “too many users” accessing it.