Cajeros automáticos—automatic teller machines, or ATMs.
When you're backpacking from Guatemala to Patagonia, there's nothing like a cajero automático to save the day.
I recall backpacking “back in the day” before the ubiquity of ATMs and before global acceptance of credit cards. Running out of money was a real threat and replenishing the stash always a hassle.
The production began with staking out a bank that had reasonable lines. On Monday mornings, for example, many Central and South American bank lines wrap around the block, easily surpassing a two-hour wait. So you definitely didn't want to run out of green stuff over the weekend.
Once inside, past the posted sentries with shotguns, I always seemed to end up in the wrong line. I'd reach the counter, utter my trite phrase “Necessito cambiar algun dinero, por favor” (I need to change some money), and often be shuffled off to another line or some obscure corner desk.
Bank officers are some of the most patient people I've ever met, dealing with broken Spanish all day as tourists attempt to exchange currency. Their first request is always for the passport, so out it comes, instinctually, like your driver's license when you look in the rearview mirror and watch the fuzz walking up.
After your credentials have been validated, you have to dig out the stack of U.S. bills or traveler's checks or some combination thereof from whatever coffer or compartment you've hidden them, often half undressing in the process ...