I gotta agree with Shelby, getting up is the best part of a vacation. You go there to see diffent parts of the world. why sleep in until 10 or 11. You can do it on a normal sat. or sun. at home.
But i would not be too concerned about bringing a cell phone on board. Why do you need to have others be in touch with you. Vacations are for being left alone with your loved ones and enjoy without any interference from Jealous friends or family members.
As everyone else has mentioned on this thread, stateroom phones have a wake up call feature. Use it frequently.