If you use your cellular phone, please be discreet about it!
As a city-dweller, part of what I'm looking to escape from on my cruise is cell phones, not to mention the people who feel compelled to loudly discuss every detail of their lives.
I understand why people have cell phones (I have one), but I really hope the pool deck doesn't get added to the places where all you hear are loud, irritating ring-tones and boisterous, one-sided conversations.
For me, a large part of the appeal of a cruise is leaving the cell phone, pager, and laptop behind and just enjoying a week of zero responsibility. If you anticipate some potential for an emergency, the cruise lines can get a message to you anywhere in the world. I say, leave that phone behind and enjoy yourself!