PC: Click on the size links above. It will open another web browser. Right Click on image and set as desktop background.

MAC: For OS 9 CTL+click on the link and save to your hard drive. Under the apple menu under control panel select appearances. Click on the desktop tab and "set desktop." From there, browse the hard drive and select your image.

For OS X: CTL+click on the image and save it to your hard drive. Open your system preferences and click on the desktop icon. From there drag the image you want into the "current desktop picture" thumbnail.