Is there any tool that will make it dead-easy to quarter the size of an image (i.e., de-Retina it)? Problem: when I take Screenshots on my retina mac using the built-in screen capture tool and attach them to certain tools (Outlook 2011, HipChat, etc.), they are enormous.

Usually to get around this problem, I'll resize them using Preview or I'll take the screenshots using Skitch.  But I'd love it if there was a way that I could simply select something from the right-click menu on the image and it would reduce the size to 1/4 (i.e., half the width).
Automator

You can use OS X's Automator.app to quickly resize images to 1/4 of their original size. The Actions you want are:


Get Selected Finder Items
Scale Images




You can create droplet like applications using Automator to make the whole process a single drag-and-drop. Alternatively you can set up a folder action to resize any image dropped into a folder.

To learn more about using Automator, see Apple's Mac Basics: Automator.