Wonderful foods I have met in North America:

• Pluots (aka dino eggs - a complex kind of plum-apricot cross).
• Huckleberries - ridiculously expensive at $6 for a tiny punnet, but delicious. (I thought of it as a touristy thing to do, like seeing the pyramids.) They look like they're difficult to harvest and keep very poorly. Would be a great plant to grow, to pick the berries and eat straight from the garden.
• Marionberry jam (a complex kind of blackberry-raspberry-dewberry cross)
• Chipotle -  smoke-dried, often sweet, jalapeño chilis. I'd only heard of them in chipotle dressing in Subway, and that doesn't count - a poor echo of the real thing.
• Mole - chocolate is too good to leave until dessert.

Honorable mention (merely great, as opposed to "to die for"):

• Beavertail cactus, used in a very good Mexican dish I had the other day.

You may be able to get some of these in Australia, but for me, these were all new.

Weird sidenote: I went looking for corn thins in a US supermarket, thinking they must have something similar to the delicious Australian "Real Foods" brand corn thins. I found... the Australian corn thins. Talk about coals to Newcastle. Corn just isn't a major ingredient in Australian food the way it is in the US (even our generic brand cornstarch is made from wheat) so I can only guess that they've got out some special way of making them.

And I'm assuming that they're shipped across the Pacific, so the sea journey is probably a small component of the carbon impact.

A few things strike me about America:

• Americans are friendly, which I really like. I'd heard this, but it particularly struck me after Europe. (I'd also heard that Australians are friendly, but didn't appreciate that till Europe.) An interesting thing to watch is how easily people make eye contact with you. Americans (in Boston anyway) do it more easily than Europeans
  
• Americans are more patient than I expected. The pedestrian crossings in Boston - "crosswalks" - are different to what I'm used to, not to mention that the most basic part of my brain still believe that cars drive on the left, so I've got it wrong a few times. Now, I might have expected them to lean out the window and shout abuse, possibly wave a gun. But no - I've even had an SUV stop and wave this poor confused foreigner across the road, when there was no crossing of any kind. (i had a similar thing in Iceland, actually.)
• The light switches go the opposite way to what I'm used to (i.e. up is on, in America). It's just seems odd that I never knew.
• Is there anything you can't put corn syrup in? At the supermarket, I looked for wholemeal bread - "whole wheat" which I admit is more logical, and couldn't find one that didn't have corn syrup! I prefer my bread without sugar of any kind. But another time I found "Yoga bread" which has sunflower seeds and cranberries in it; and it's easier to find unadulterated peanut butter than it is in Australia (the only acceptable additive is salt, in my view).
  

All of this is based on a very limited experience of Europe (a few places in the Netherlands, London, and Iceland) and America (Boston, and one day in Denver... Ontario isn't America, but it fits the pattern for everything except the corn syrup).