There is free wi-fi in the Aria and Venetian poker rooms. So I use my UK phone there for skype, fb, email etc all the time. Might save some people buying the in room internet if you don"t need it much.
And buy 1 UK-USA adapter and bring a UK 4-gang extension. Then you have 4 UK sockets in your room for you and whoever you share with. Enough for 2 laptops and 2 phone chargers etc, no fighting over the 1 adapter.