My iPod Touch / iPhone is frozen!

My iDevice is frozen on one screen and won't let me do anything. What can I do to fix it?

Hold the Home Button and Power/Sleep buttons together until it hard resets.

You can force-quit the currently-open app by holding down the power/sleep button until the "slide to power off" screen comes up. Then you hold down the home button until the app is closed.

This may not work if the entire device is completely frozen.