Living in the hotel, remember that often when calling from numbers you need to leave a deposit to connect your phone.
To make calls to the United States should dial 1 + area code + number,
To make calls from the United States: 011 + country code + area code + number.
To make calls from a mobile phone take care of the roaming connection, and the phone must support GSM 1900 standard.
With automatic phone calls less expensive than the hotel. In the US, a sufficient number of telephone machines. Another way to save is with prepaid phone cards.