One my Australian friends recently observed to me that Americans tend to have random, quirky, specialized interests. I'm not sure how scientific this theory is, but I see what he's getting at. There's the collections for one thing. My mom has lots of pictures of chickens. Another American friend collects everything moose related. Most American households have at least one fish-themed bathroom, too, but potentially that's another blog post altogether.
Then there's hobbies. My (Australian) boyfriend's sepak takraw obsession notwithstanding, Americans tend to have kind of quirky pastimes. (Okay, now I go to think of them my mind's gone blank. All I can come up with genuine anecdotal evidence of is racquetball, quilting and dumpster diving -- none of which are that unusual and all of which are also done here.) I'll get back to you on precisely what.
Another realm is that of obscure knowledge. I'll consider myself a prime example here. I'm no expert, but I can still tell you everything I learned in elementary school (and I was a pretty darn good student) about Marie Curie, Marie Antoinette, Abigail Adams, Cleopatra, many American presidents and, for the clincher, Idaho. (It's the Gem State.)
I'm sure you could argue all of this could apply in Australia, too, but, well, I'm not arguing that point at the moment. It was a genuine comment from a genuine Australian that Americans are oddly intrigued ... and, well, I think I'm really kind of proud of it.