For everyone who uses Cmd-Shift-4, try Cmd-Cntrl-Shift-4 to accomplish the same thing without risking a 31px by 2px file cluttering your desktop when you don't click Esc on time.
Note: this saves the image to your clipboard instead, overwriting anything you've cut/copied.
Another great reason to have a clipboard manager.
Very true and I can't imagine using any device without a multi-clipboard manager. I'm pretty surprised Windows, OS X, Android, iOS, etc. don't already have them built-in by now or at least optional within the system preferences somewhere.