If I walk into a post office in Canada today and ask for a $50 money order, the clerk will automatically ask "Canadian or American?" because so busy is the trade between these two countries that the one is as common as the other.
The American dollar right now is sitting below parody with both the Australian & Canadian dollars and shows no sign of improving over the next 12 months so, no sense in holding off with regards to foreign trade.
Regardless; If you check on E-bay, you will find that even Canadians are dealing in American dollars. (it's just easier that way) So no need to worry your pretty little head about exchange rates and such.