Windows: Click the following file you would
like to set as your desktop wallpaper. This
will open a new browser with the image you select.
After the image loads in your browser, right
click on it and select set as background.
Mac OSX: Command-click the link to the image
you would like to set as your desktop wallpaper.
Save the file to disk. From the Apple menu,
select "System Preferences > Personal
> Desktop". Find the image and drag
it into the Image Well.