Denver or Detroit
A few months back I was returning home from a guy's weekend in Wisconsin and had woken up late, dashed to the airport, and jogged onto my flight. I nodded off as soon as I took my seat for the flight to Detroit, where I'd connect to New York. I came to after we touched down and tried to peer over my neighbors to see out the window, but it was a wash of fog. I turned on my phone to check-in on Foursquare, and found myself looking at a list of places near the Denver airport. My pulse quickening and panic creeping up my spine, I tried to look out the window again, and seeing nothing, turned on Google Maps to also find myself in Denver. Now, near full-blown panic, I asked the man next to me: "Where are we?" I'm not sure if his look was concern for my well-being or concern for his own safety, but either way he said, "Detroit" and I relaxed. Turns out the GPS on my phone never worked. It would ping WiFi when I was in the city to get a fix, and it was always a bit off, but I never noticed until it saw the airport WiFi and put in Denver.