A bit off topic, but I wanted to comment on U.S. visa part (when the author realizes that valid visa was in the passport he did not have with him) in hopes that

A bit off topic, but I wanted to comment on U.S. visa part (when the author realizes that valid visa was in the passport he did not have with him) in hopes that it may be useful for someone. I was in a similar situation, except that was an overland crossing from Canada. I had new non-Canadian passport with me and driving up to the border I realized that my expired passport with valid US visa was left at home, 4 hours of driving away. That was especially embarrassing as I had friends in my car. Turns out that after me contributing around 500$ to Uncle Sam coffins they can pull visa information and previous entry records and admit me into the country after getting authorization from higher ranking officer. Usual disclaimer: it may or may not work for you, especially for air travel, and that was back in 2007.