When I was younger I lost many wallets, so for about ten years I either used a rubber band, or a money clip. But about 10 years ago, for practicle purposes I started carrying a wallet again, and it started to become like a Costanza wallet. So, two years ago, I bought a FOSSIL slim executive wallet. It has one vertical, and one horizontal flap, so I can easily access my identification, or my credit cards; or have room for cash. It's so thin, I can comfortably store it in a suit jacket, or even my front pants pockets, which I often do. I hate sticking my wallet in the back pocket of my pants. With my wallet you can't even tell I'm carrying it. And the quality of this wallet is excellent. As long as they'll continue to make them, I'll never own a different one. It's 100% leather, and I've never had a magetic strip issue.
When closed its probably 2.5 x 3" and about 1/2" thick.
I love this wallet so much I'd be a spokesperson and they wouldn't have to pay me.