Capture the Screen with Mountain Lion's Grab
Want to take a picture of your Mac screen? You can use Grab in OS X Mountain Lion to take a picture of all or part of the screen and save that file for printing or sending around (say, to all your screaming fans who want to see your Desktop pattern or how you’ve organized your windows).
Grab’s best feature is its capability to do a timed screen capture. Like those cameras that let you start the timer and then run to get into the shot, Grab gives you 10 seconds to bring the window you want to the front, pull down a menu, and get the cursor out of the way or whatever you need to do to get the screen just right.
Grab’s default behavior is to display no cursor. If you want to show a cursor in your screen shots, choose Grab→Preferences and then select a pointer from the ten choices in the Preference dialog. To have no cursor, click the topmost, leftmost item, which is an empty box that indicates no cursor.