Checking your Smartphone: Not Smart

The accounting firm, Deloitte, recently studied smartphone usage.  There are 185 million smartphones used in the U.S. They found that the overall average times a person checked his phone during the day was 46.  I suspect, however, that a salesperson checks his phone about 100 times a day.
The absolute worst thing a salesperson can do in the presence of a customer is to check his cell phone during a sales call or presentation.  Even if you're not the primary presenter, you should never consult your phone unless it is directly related to a question asked by the customer, after asking for permission.
Turn your cellphone off; leave it in the car; do NOT consult your cellphone in the presence of a customer.  This is the epitome of disrespect.