To download an image,
right-click if you are on a PC (click and hold your mouse button
if you are on a Mac) on the 'Download a hi-res jpeg' link under
the image you want. From the menu that appears, select the option
to 'Save target as' (PC) or 'download link to disk' (Mac). You
can then select where on your hard drive you would like to save
the image.