I think you are missing the point, obscure2k. When learning about and adopting the customs and habits of a culture that one visits, a traveller is showing courtesy, respect, and a recognition that s/he is a guest in someone else's country and culture. That is not at all the same as trying to "pass."

To respond specifically to your question, when I see tourists who appear to be non-American visit the U.S., it's not uncommon to see them trying to imitate Americans. They might be wearing T-shirts announcing that they've visited Cape Cod, but, given that they're jibber-jabbering to each other in Italian or Japanese and appearing to be having a wonderful time, it hardly strikes me that they're trying to pass as Americans.

Same thing when I visit Paris or Hong Kong. In the latter I'll use my knife and fork as the French do (and no, the bread is not used as a little snow shovel) and in the former I'll use chopsticks, but it's extremely unlikely that anyone would believe that I am passing myself off as either French or Cantonese. I'm simply trying to show respect for the people and land that I'm visiting.