Resolution: 1600x1200

MAC:
CNTRL + click on the image to save to your hardrive, OS9: Under the Apple menu, open Control Panel / Appearances, Click on the desktop tab, then click Set Desktop. OSX: Open Your Systems Preferences and click on the desktop icon, Drag the image you want as your desktop into the Current Desktop Picture thumbnail.

 

PC:
Select a resolution below by clicking the appropriate download link, once the images id opened in a browser window, right-click on the image and select Set as Wallpaper