Firstly, download the NatGeoWallpaperDownloader (NGDL.exe) from here
Run the app, choose the folders you wish to d/l, set the destination folder and pic size, and go for it.
Note. There are 2 sites to download from. (The downloader will be updated as new pics become available so it should be replaced when you want to have another look. Provided you pick the same location and pic size, this app will check for existing photos before d/ling new ones. This is important as there are several thousand available.)
Edited by rowal5555, 26 September 2010 - 04:03 AM.