The URL File Plug-In

GIMP can load an image directly from an HTTP or FTP server. The image can be in any of the formats that GIMP recognises. To open the file, simply type the full URL (Uniform Resource Location) as the selection, e.g. http://www.gimp.org/wilber.jpg. You can either specify the file type as URL or Automatic, and click OK. GIMP will display its progress as it downloads the image to a temporary directory.