Just be sure you leave a copy of your itinerary and the name of ths ship you are on. I know that may sound dumb, but if my kids had to tell someone what ship we were on, they wouldn't have a clue.
Mary Lou Scanlon
NCL Pride of America April 24, 2010
NCL Epic February 12, 2011
RCCL Allure of the Seas - September 18, 2011
Celebrity Eclipse - February 11, 2012:
RCCL Navigator OTS - February 9, 2013
By all means take Mike's advice. Leave instructions to not call unless it is absolutely an emergency you have to deal with. There's no reason to upset you while you're on vacation when you can't do anything about it. It only raises your anxiety and frustration levels while you're suppose to be having a good time.
On the other hand, if the kids want to tell you about the soccer game they won, or that Hunter the dog went to the vet because of the alley cat he swallowed, there are email and internet services in most ports for about $5 per hour versus the $50 for 100 minutes on the ship.