Have you ever found yourself in an unfamiliar city with no clue about where to go and what to see? What if you could just hold up your phone, snap pictures of your surroundings, and discover interesting local restaurants and landmarks? With augmented-reality apps, you can do just that. But advertisers are jumping on the trend as well, so the same application that reveals intriguing potential destinations might also bombard you with ads for nearby fast-food chains. Can augmented reality actually be useful for consumers, or is it simply another way for corporations to get a hand in your wallet?