But for MagicJsck, unless you are going to lug a laptop everywhere you go, and are assured of an Internet connection EVERYWHERE, a cell or SIM card is still the way to go IMO. You said you wanted to be reachable by your father.....and you won't be staying in the room all of the time.

If your magicJack is plugged into your computer, the computer must be on and you must have an active Internet connection to be able to place and receive calls.
It is also good to have peace of mind to be able to reach someone if your rental car breaks down....or you're laying on the beach and inspiration suddenly hits for where you want to have dinner, you can call and make a reservation, <img src="http://www.traveltalkonline.com/forums/images/graemlins/Wink.gif" alt="" />