I tend to look at my phone when I am nervous or bored but have you ever caught yourself pulling out your iPhone, or your Droid, or your BlackBerry and looking at the screen, even though it didn't vibrate or ring?
Yeah . . . everyone does it.
According to CNN and a study in the journal "Personal and Ubiquitous Computing", the average smartphone user checks their phone 34 times a day for NO REASON. It's just out of habit.