Ah - good choice - this is one of my favourites! I suppose you what to know how to get it on the desktop now. Setting the background as your desktop wallpaper can be done in a number of ways. One way is to right click the desktop background below and then choose 'save target as...' (IE & Opera) or 'save link as...' (Firefox). Don't forget where you saved it though! Next goto your computers display control panel and set the background to the image you just saved.
A different way altogether is to right click the background below, from here choose 'save image as...' or 'set as Desktop Background' or 'Set as Background'. It'll come to you when the time is right. I believe in you. I bet you already know. I'll shut up now.
Return to wallpaper thumbnails.