Question for all those who travel or live in the great white north. I am planning on a week long driving trip through Southern Ontario and am wondering what to do about cellular phone service. I would only have it for reserving hotels along the way and emergencies. I was wondering what other American travelers have done, International roaming, (I have ATT), or get a Canadian SIM card for my unlocked GSM phone and buy some pay-as-you-go minutes? Thanks in advance for any advice/experiences you can share!