OS X screenshots - format & location

Set location & format for OS X screen shots circa OS X 10.4

default shortcut keys are:

Save picture of screen to file: ⌘⇧3
Copy picture of screen to clipboard: ⌘⌃⇧3

Save picture of selected area to file: ⌘⇧4
Copy picture of selected area to clipboard: ⌘⌃⇧4

To modify the location open a terminal window and type:
defaults write com.apple.screencapture location /Users/username/pictures/Screenshots/

I choose to put my screenshots in a folder called 'Screenshots' which is in my Pictures folder.

To modify the format you are using type:
defaults write com.apple.screencapture type image_format

eg.
defaults write com.apple.screencapture type jpg

Replace image_format with your preferred image format; PNG, JPG, TIFF, PICT and I think PDF maybe

You may then have to logout/login to make the change(s) take effect, or try this command in your Terminal window:
killall SystemUIServer

Although Leopard may have done away with this necessity.