Not sure about what to bring back.
Of course, if you're in NY, you could always get some pizza. Never had any myself, but I'm told it's the finest and best that can be had.
How about... *scratches head*
A ruler in Inches?
An American-made American product, other than cigarettes. (Oh, wait, that's a trick question. Never mind.)
A truck-load of illegal immigrants? (Actually, we'll give you those for free.)
A copy of the Declaration of Independence? (Ooh... that was mean. *slaps hand*)
You know, now that I think about it, I'm not sure what's really "Authentic American" anymore. We import so much stuff, I sometimes think we're losing our own sense of self over here.