Exactly the "one-trick-pony" I needed :D

Allows me to quickly toggle the faux-Retina HiDPI resolution on my non-Retina MBP for testing hi-res artwork.

Its a pain to use the System Preferences Display pane, which (sensibly) jumps front and center, covering whatever youre looking at.
With the user-defined key combination, I can avoid the extra steps. Well worth it if you have to switch back and forth repeatedly.

I will heartily second the suggestion that it could offer a checkbox to enable the HiDPI option on non-Retina screens. This way the user avoids the hassle of a) hunting down the appropriate terminal command or b) having to install Xcode just to set a checkbox once in the Quartz Debug utility.

VaughnSC about ResolutionTab