Change the format of the screenshot pictures

I've posted here before about the things I love in Mac OS X, one of them being the built-in screenshot grabbing shortcuts. If you don't know them, here's a quick tutorial:

• Command + Shift + 3 = image of the whole screen
• Command + Shift + 4 and then Spacebar = image of the chosen window
• Command + Shift + 4 and then mouse = image of specific region

All these create a PNG image file on the desktop with the captured image. You can use CTRL to transfer the captured image to the clipboard instead.

However, PNG format may not actually be the best format to output the screenshot since it is not so widely accepted as, for example, JPEG. So, if you want to change the output format of the screenshots, just execute the following command on a Terminal window:

defaults write com.apple.screencapture type jpg

Et voilá! From now on, every time you "grab" an image from your screen, the output format will be JPEG. You can also try other formats such as GIF. Just change the last part of the command to use gif instead of jpg.

And naturally, if you decide to get back to PNG, just add the png extension to the end of the command.

Source: MacTips