Command-Shift-3: Take a screenshot of the screen, and save it as a file on the desktop Command-Shift-4, then select an area: Take a screenshot of an area and save it as a file on the desktop Command-Shift-4, then space, then click a window: Take a screenshot of a window and save it as a file on the desktop Command-Control-Shift-3: Take a screenshot of the screen, and save it to the clipboard Command-Control-Shift-4, then select an area: Take a screenshot of an area and save it to the clipboard Command-Control-Shift-4, then space, then click a window: Take a screenshot of a window and save it to the clipboard In Leopard and later, the following keys can be held down while selecting an area (via Command-Shift-4 or Command-Control-Shift-4): Space, to lock the size of the selected region and instead move it when the mouse moves Shift, to resize only one edge of the selected region Option, to resize the selected region with its center as the anchor point ...