What a peach of a wallpaper don't you think? I suppose you what to know how to get it on the desktop now. Getting the wallpaper onto your desktop background can be done in a number of ways. You can either right click desktop wallpaper beow and then select 'save target as...' (IE & Opera) or 'save link as...' (Firefox). If this is your chosen route, remember where you save it! Next you need to go to where your computer's operating system display settings and set the image as your background / wallpaper.
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'. You'll know what to do when the time comes. I believe in you. I bet you've figured it out already. I'll shut it now then.
Return to wallpaper thumbnails.