Concept: 3 out of 5
Execution: 2 out of 5
Yeah, but: It only costs eight bucks.
The Long Version: There are two completely different things that are called a "money belt", and it's important to choose the right type. Some are large flat pouches that are sized to hold passports and a considerable wad of euros. These go under various articles of clothing, and aside from having a strap on them, look nothing like belts. The other style is, deceptively, an actual belt: they just have a long flat pocket on the inside, closed with a really long zipper.
The On Sight money belt is the second type, and holds bills when they're folded into quarters lengthwise. It has a minimal capacity, so don't expect to hide much more than a half-dozen pieces of your favourite currency, and it won't hold any ID or travel documents at all. Instead I keep a small strip of paper in mine with the numbers of my important documents, a mnemonic sequence for my credit card, and the phone number for the Canadian government.
The belt is made from nylon webbing material with a simple cam-lock buckle, and its ability to securely lock at any position is a kindness for travelling. The inner compartment runs nearly the full length of the belt, ending before the portion that threads through the buckle. When closed, the zipper pull is at the buckle end of the belt, making it easy to check but hard to get into. A little privacy goes a long way if you ever need access to its contents.
While there is some metal in its zipper, it's hard to imagine it setting off a metal detector. That's not to say that it's a good idea to wear clothing with concealed pockets though a security checkpoint, but since some scanners can see through clothing anyway, I'm sure we're all safe from every threat if we ever take the risk of leaving home. Use your judgement and remember just how complicated life becomes if you break the rules. (If you're not Canadian, make that "how complicated life can become if you're caught breaking the rules.")
If you typically wear clothes that need to be ironed, the On Sight money belt isn't an appropriate stylistic choice. Aesthetically it's very casual and nondescript, suiting backpackers and the sneakers-and-jeans crowd without drawing attention to itself. There's no external branding, and just the faintest wisp of visible stitching to give away its true nature. I've used mine for a couple of weekends, and the diagonally cut end that fits through the buckle is showing some minor fraying, but I choose to think that it adds to the nothing-special camouflage.
I'm comfortable with my current level of paranoia to keep me safe within North America. Rather than depending on a Type I money belt to secure all of my valuables against pickpockets or muggers, the On Sight belt serves as my last-chance get-out-of-trouble kit. It doesn't hold much, but that's enough for what it needs to do: remember to stay calm, be brave, and wait for the signs.
last updated 4 may 2011