Almost all hotels and hostels have facilities for making local and international telephone calls, but rates vary so check before calling home. You can easily find public telephones at newsstands and in shops and markets in most towns and cities. Public telephones take 100 peso coins. They are fine for making local calls but international calls are either barred or charged at very high rates.
Most towns and cities have centros de llamadas (call centers) and Internet cafés, which you can use for local and international telephone calls. Here you can make calls from a private booth or in some cases make VoIP calls, for example via Skype. The cost of international calls depends on the destination and is calculated by the minute. Expect to pay around $0.40 USD per minute to call the U.S. from Chile.
A cheaper option is to buy an international calling card from a newsstand. These prepaid phone cards come charged with calling credit and you can use them to make local and international calls to and from any phone.