I blame the cafes and their glut of damnable loyalty cards.
If, like me, carrying your regular wallet in your trouser pocket makes it look like you're smuggling a shoebox jammed full of cash, then you might want to take a look at the Bellroy Travel Wallet.
The key to travelling light, is to pack smart they don't come much smarter than this. Your wallet is no different from your suitcase when it comes to packing smart. The BTW cleverly places card slots alongside each other, rather than on top of on another, effectively halving the depth of the wallet. Consequently, it's long and wide.
When folded, the wallet is 15cm long - which is pretty long. It's 9.4cm wide. That's pretty much the size of your passport, which fits neatly into an internal sleeve. Very clever.
Crucially, it's thin. On a recent trip to the US, the wallet sat flat in my front jean pocket with the passport inside it. No mean feat.