If you’re an efficiency/productivity nut like I am you are probably also obsessed with keyboard shortcuts. One of the main ones for me is the ability to close documents in OS X without saving them.
So, given the dialog above, how do you select “Don’t Save” without using your mouse? You can’t use the arrow keys, and you can’t use the tab key. It was annoying me, so I looked it up.
Turns out it’s simple enough: ⌘-D — for “Don’t Save”. :)
[ Edit: Evidently you can also just hit the spacebar if you have full keyboard access turned on. Thanks Jon. ]