Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
apple-shift-3 for a full screen
apple-shift-4 for crosshairs that let you drag over the area you want in the pic

they save to the desktop as png files

More in Apple > System Preferences > Keyboard & Mouse > Keyboard Shortcuts
 
CMD+Shift+3 for a full screen shot and CMD+Shift+4 to bring up cross hairs to select what you want to take a screen of... 🙂
 
There's a utility called Grab that gives you a little more control. It's in Applications<Utilities.

Also, Apple Help has answers to a lot of these questions. =)
 
To clarify these responses, "Command" is the official name for what some are calling the "Apple" key.

You may also hear it called "Flower" from old-timers.

They are all the same key; the key with the Apple and the squigly line thing.
 
Add me on to this question! I own a 2009 IMac desktop and have no idea how to take a screen shot. Can someone give me a step-by-step explanation?
Did you not read the thread? I don't think it could be answered any more completely.
 
There's a utility called Grab that gives you a little more control. It's in Applications<Utilities.

Also, Apple Help has answers to a lot of these questions. =)

I only just saw this this week, is it new in 10.6.6 or have I just ignored it for ages??? It's good and helpful either way if you can't remember the shortcuts! 🙄
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.