The BigStock blog has a great visual article showing some key differences. Here's some of our favorites!
Trainer:
![20 BRITISH WORDS THAT MEAN SOMETHING TOTALLY DIFFERENT IN THE U.S. trainer](http://static1.squarespace.com/static/5176fdb5e4b083b631f31303/t/521778dce4b0a0f230fd06db/1377269981969/britain_us-trainer2.jpg?format=750w)
BRACES:
CHIPS:
(also, expect funny looks if you eat yours with mayo in the US, especially if you whip a tube out on a picnic)
Read the full article here.
Oh, and needless to say, order your prepaid USA SIM card before you leave the UK from Telaway!