Yes - Through an accident of history, Canada, the USA & much of the Caribbean share the same country code, but its still international.

Yes, as you will be roaming onto a Canadian cell provider's network (likely Rogers).

If your phone is unlocked, and you must use it, there is some more background on options here -

http://www.flyertalk.com/forum/canad...e-options.html

Summary seems to be that this is the easiest option:

http://www.similicious.com/