We do love ourselves some AR (augmented reality) apps around here, so devs, just add AR to your app to get featured here. Just kidding, but it doesn't hurt.
Case in point is this nifty little app called Heads Up Compass. It uses the camera's live feed and overlays the compass headings in cardinal points and direction on top, allowing you to scan the horizon for Tusken Raiders. Or maybe Bear Grylis.
We actually have no practical use of this outside of looking bad ass in New York City when we get out of the subway. That didn't stop us from buying it for $0.99 though. Of course you could use it for free (with ads) if you don't want to spend the buck.
Grab Heads Up Compass here in the Marketplace. And good luck finding R2.