Depends on what usage profile (voice local, voice intl, data) and amount of use. Also, how long are you going for. As mentioned earlier, also depends on what Vzn phone you have. If it's a global phone:

1) for data, use VZN's global data plan - it's a good deal
2) if voice use is minor, suffer and pay the appx $1 per minute
3) if you're going to use a lot of voice, get a local phone #. If you have a GSM tri/quad band phone, you can buy a SIM - last time I bought a TIM card. It was a hassle to get it turned on but it did work.