Hi Nik,
Yes I can understand how you would want to avoid using your mobile phone from abroad to phone home as it can be ridiculously expensive.
The most inexpensive and certainly easiest way of phoning home from America is by purchasing a phone card. Your hotel should have these available to sell to tourists such as yourself which you can then use on the hotels public telephones. They will offer great phone rates which can be used to call many different countries.
If for any reason your hotel does not supply phone cards, you will not have a problem in finding a convenience store in close proximity to the hotel which supplies them. The hotel staff who are familiar with the area will be more than happy to help you obtain an international phone card. Do not worry, they are very common and it is easy to find a store which sells them.
If you have any further questions then please do not hesitate to email me.
Kind regards
Cheryl, your editor