Some countries have silly limits on the amount of currency you are allowed to take out of the country. Bitcoin can function as cash in some instances and it adds to your spending budget, if you have a extra

method of payment. It's so convenient and fast, and hassle-free. You also have a lower risk of theft / loss when you travel abroad and you have no safe way to store your currency.

I would rather walk around with a mobile phone and draw little attention to myself, than carrying a wad of cash and painting a target on my back to all pick pockets out there.