This wearable safe for keeping your passport, credit cards, and spare cash secure is the one indispensable accessory every traveler loves to hate
Picture a fanny pack (Brits: picture a bum bag). Now picture Wiley E. Coyote running over it with a steamroller. That's your moneybelt.
This portable safe is a flat pouch with a zippered compartment (the better ones have two compartments) that holds your passport, plane ticket/voucher, railpass, bank ATM cards and credit cards, B&B vouchers, emergency cash, spare copy of your backup info sheet, and anything else that would ruin your trip were you to lose it to pickpockets or bad luck.
You zipper all that stuff in there, buckle it around your waist under your clothes, and ain't no pickpocket getting to your goodies.
The different kinds of moneybelt
Up above, I described the classic, waist belt kind of moneybelt, but there are other flavors, including one that hangs around your neck like a tiny purse (unless you have six-pack abs, this tends to accentuate your belly with a big rectangle), and one that attaches to your belt by a loop and hangs down your pant leg (also small, and awkward in that you have to reach waaay down your pants to get at it).
There are also various silly little models, including those that strap to your ankle wrist (not large enough to hold a passport, hence pointless, to my mind, but some folks like them for carrying around a secret stash of cash and such), plus a sort that clips to your bra (again, too small for passports).
Also, if you're going anywhere where swimming might feature in your plans, I recommend carrying along a waterproof moneybelt into which you can put your moneybelt items, seal shut, and take with you into the water.
Actual "money belts"—Leather belts with a secret zippered pocket
In addition to your moneybelt for carrying your passport, documents, and credit cards, you might also want to wear a traditional leather belt that just so happens to have a hidden zipper on the inside—perfect for hiding some emergency cash and an extra copy of that backup info sheet (a photocopy of your passport and other important documents); just fold the bills and such into thirds the long way, layer them, and they'll all fit.
Proper use and care of your moneybelt
No matter which kind you get, always, always, always wear your moneybelt underneath your clothes, as nature intended it. Sure, they're a pain to get into as you must either reach down your shirt or down the front of your pants every time you want to pay a big restaurant bill, hit the ATM, or check into a hotel.
But keeping this sucker tucked away is the only way it'll work. It’s not that your stuff is "hidden" this way—every thief in Europe knows about Americans and their moneybelt—it's just that it keeps your valuable documents inaccessible to them.
I see countless travelers wearing the waist style on top of their pants like the world's flattest fannypack, or the neck kind bouncing around on their belly like a tiny purse. You can even see through the thin nylon fabric of the things to their passport, credit cards, and folded up wad of emergency $20s.
Stupid, stupid, stupid.
Exposed like this, moneybelts actually make your most precious documents even less safe than they would be if you simply stuffed them in your pockets, the tops sticking out, with convenient little loops attached so pickpocket can more easily relieve you of them.
I tend to go up these people on the street and scold them, so please don't do it yourself. Nothing spoils your day like a deranged and testy travel writer accosting you on a Parisian bus and yelling at you about your moneybelt habits.
Do not carry what you do not need
Incidentally, please leave at home all unnecessary wallet items—library card, gas station credit cards, your membership in the "cheese of the month club" that's good for 10% off on gouda, etc.
There's no reason to carry them around the streets of Paris.
While we're on the subject, leave at home all keys but your main house key—that you keep tucked away in your main bag, somewhere safe.
On overnight train rides (and in hostels and other shared accommodations), I tend to excuse myself to the bathroom just before bed to brush my teeth (with bottled water, of course; you can't drink the water on trains), and while there re-strap my moneybelt around my upper thigh rather than my waist.
This way, at least your valuables are extra secure.