If you plan on using your cell phone for more than emergencies while traveling, you should get a local SIM card and phone number. This is also an ideal way if you are traveling with kids to keep in touch since each one can get a local number and calls aren't very expansive between them. It involves visiting a cellular provider's store in the country you are visiting and asking for a local prepaid service. You get a local phone number and it generally costs around 10-40 dollars with some included credit if you already have a phone. If you are confused, don't give up, everything is explained below.
Local phone number.
Don't usually pay for receiving calls.
Some airtime credit included when purchasing SIM card.
No monthly bill, prepay the airtime you plan on using.
Credit can be purchased at many location in the visiting country.
Need an unlocked GSM cellphone.
New phone number while abroad.
Added effort to buy a SIM card in the country visiting.
Documentation such as a Passport might be required.
Credit can only be purchased in country where SIM card was purchased.
More information will be posted shortly.