I hear now you don't need a passport to re-enter the USA if you have two forms of photo ID. I always take my passport with me just in case. At certain times there are long lines to get back. If you've had dental surgery, you can go to the front of line 'with permission' and 'pass' the line. Also anyone over 60 is permitted to jump the queue. Great dentists and doctors within walking distance not to mention fine dining and sushi.