Shortcuts
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
Formats
Different versions of Mac OS X have different formats for screenshots.
Mac OS X 10.2 (Jaguar): jpg
Mac OS X 10.3 (Panther): pdf
Mac OS X 10.4 (Tiger) and later: png
In Mac OS X 10.4 and later, the default screenshot format can be changed, by opening Terminal (located at /Applications/Utilities/Terminal) and typing in:
defaults write com.apple.screencapture type image_format
killall SystemUIServer
Where image_format is one of jpg, tiff, pdf, png, bmp or pict (among others). If you omit the second line, you will need to log out and in again for the change to take effect.
