Your iPhone's compass is a feature you may not know about, but it can save your life. However, you'll need to calibrate it ...

To aid the calibration process, follow the onscreen animation. After the device is calibrated, the compass screen displays. Hold the iPhone parallel to the ground with the screen facing up.

The Compass app comes built-in on every new iPhone, and it's helpful when you want to make sure you're going in the right direction. Here's how to launch the app, calibrate it, and use it to find ...