Once again, an incomplete response from the resident "know-it-all".
There's no mention if you can turn on your phone while roaming and if you are charged to receive SMS while roaming too. Sometimes even if you turn on your phone and data is disabled, you are still dinged a fee. That's not typically the case with the Big Three though. As long as you don't answer the call, retrieve your voice mail, or send an SMS while roaming, there's no charge. Just ensure your [cellular] data is disabled when roaming.