According to the Pew Research Center, more than 90 percent of American adults own a cell phone, and 67 percent say they find themselves checking their phones constantly, even in the absence of an alert sound or vibration. Many experts think this behavior smacks of codependence—even addiction. Are you brave enough to find out about the depth of your own mobile addiction? Then consult the checklist below, which aims to help you diagnose your 'nomophobia', or fear of being without your phone. Be sure to let us know the extent of your 'disease' in the comments below.