[QUOTE=KeyboardR;6867952]How does currency conversion work? I assume they don't just take credit card.[/QUOTE]Several ways to accomplish this (and the last / least way would be pay by CC).
You can convert your USD at yours (or any othe US bank) into CAD and the exchange would be whatever their 'money desk' has posted.
You can hit the duty-free shop at the border (I did this yesterday) and my $150 became $190 so about a 79% exchange rate.
You can use a Canadian ATM and accept the $3 fee, their exchange rate and whatever your bank charges for an out-of-country transaction.
You can pay w / CC but are going to be hit with a GST of about 10% on top of the actual cost.
I usually opt for #2.
