The moon rises over the Capitol Quadriga. | Photo by Andrew VonBank
For Windows users, place your cursor over a picture and right click once which will pop up a window that will include the following options (depending on what browser you are using): "Save Image as" or "Save Picture as." Select an option. Then choose where on your computer you would like to save the image, and what you would like to name it.
For Macintosh users, the simplest method is to click
and drag the image from the web browser to your desktop. An
alternative is to cltrl-click
(or right-click if you've got a two-button mouse) on the image and then select
"Save Image As..." from the contextual menu.