Careful with this one - can be slippery when wet. Do you need to know how to put this on your desktop? To get your chosen wallpaper to be set as your desktop background can be done in many 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! Now go to wherever it is you normally set your desktop backgrounds for your computer and selected the saved wallpaper.
Another way is when the full screen wallpaper is shown, right click it and select 'save image as...' or 'set as Desktop Background' or 'Set as Background'. You'll have a flash of inspiration when the time comes. I trust you. In fact you probably already know. I'll shut it now then.
Return to wallpaper thumbnails.