A quick way of changing the default file format for Grab.app (or ‘Command + Shift + 4′ short-cut) from .tiff to other formats such as .pdf, .png, or .psd etc.. Choose any of the following line and paste it in your Terminal window and press the return key, that’s it.

defaults write com.apple.screencapture type png
defaults write com.apple.screencapture type pdf
defaults write com.apple.screencapture type jpg
defaults write com.apple.screencapture type tif
defaults write com.apple.screencapture type psd


IMPORTANT: You have to log out immediately in order for this change to take effect!!

By the way, here is a list of short-cuts for making a screenshot quickly:
Screen to file:
Command + Shift + 3

Screen to clipboard:
Command + Control + Shift + 3

Crosshair screen selection to file:
Command + Shift + 4

Crosshair screen selection to clipboard:
Command + Control + Shift + 4

Window to file:
Hit spacebar after invoking 'Command + Shift + 4', then click the appropriate window

Window to clipboard:
Hit spacebar after invoking 'Command + Control + Shift + 4' then click the appropriate window

A pretty handy tip I picked up from the Mac OS X Hints. If you tend to open multiple Finder windows for organising/moving folder/files on the Mac OS X. This script helps to reduce the time after you open a new instance of Finder (ctrl + N) and navigate through endless sub-directories to reach the folder you want.

In more details, this Applescript gets the location of the front-most Finder window and opens a second instance of Finder with the same path and view. If there is no Finder windows at the present when this script is executed, it launches a new Finder window at the system root directory (or any other pre-defined target path).

tell application "Finder"
get the exists of the front Finder window
if the (exists of the front Finder window) is true then
try
set newWindow to target of front window
set oldView to current view of front window
make new Finder window to newWindow
set current view of front window to oldView
end try
else
try
make new Finder window to alias ":"
set the current view of the front Finder window to column view
end try
end if
end tell


Copy above script and paste it to the new project window opened via the ‘Script Editor.app’ (Applications/AppleScript/), then choose ‘application’ as the ‘File Format’ and then save/compile the project with a meaningful name such as ‘CloneFinder’. Once that is done, drag ‘n drop the newly compiled CloneFinder.app on to the Finder tool-bar for quick access!!