Bitcoin's characteristics seem to make it a prime candidate as a reserve currency, given it has fast transactions to anywhere in the world at a low cost with little to no price manipulation or export/import controls.
Imagine a traveller arriving in a foreign country, having bought 100 Bitcoins in his country. Rather than go through a middle-man currency exchange, he finds someone who wants Bitcoins (or even a Bitcoin ATM) and sell his Bitcoins for local currency. When he is ready to leave, he simply sells back his local cash for Bitcoins without being hit twice by the currency exchange's transaction fees.
What would have to happen to make this a reality? Is it feasible?