Hi Everyone I am an Aussie going to the USA, Canada and Alaska for 7 weeks in a few months and need to get good information about prepaid sims for iPhone 4s, ipad2 and iPad3 before we leave on our trip. Want to be able to go to correct retailer when we arrive and get set up straight away. Also, does the USA sim work in Canada. We will be travelling Boston, NYC, Washington dc, Chicago, Seattle, Vancouver, Victoria, Rockies etc. we will then cruise up to Juneau etc. Have heard all sorts of tales about how difficult it is but thought this place would have the correct info.