

When you want to show someone how to do something on a Mac a picture often helps out quite a bit.
I was using the included utility GRAB as it will capture your screen shot. My frustration with this is that it saves the image as a .tiff and then you have to open it with another program and do a save as .jpg
Tiff is a high quality file, yet very large and not good for emailing and useless for posting in blogs.
JPG is a compressed file that is much smaller than a .tif and will display in any web browser or email.
So here is the hidden shortcut that will save your screen shots as .jpg
use keyboard short-cuts:
APPLE-SHIFT-3 for your entire screen exactly as you see it
APPLE-SHIFT-4 to select a region using cross-hairs to draw a box.
Your new screen shots are now stored in your Pictures folder under SCREENSHOTS i.e. HOME/PICTURES/SCREENSHOTS
The pictures will be named sequentially and this is a fault with this method as you don't get to name each picture as it's made.
You may need to run a program named TINKERTOOL one time to set the screen capture format to .jpg
Tinkertool can be found here
http://www.bresink.de/osx/TinkerTool.html and it's free.