Your collection of card carriers is pretty big. My card carrier of choice was not included. Here's mine. Fan&Ran Genuine Leather Journal Cover for Field Notes Notebooks, Moleskine Cahier Journal Pocket 3.5 x 5.5 Inches, Bourbon Brown

It allows me to carry 8-10 3X5 cards. It has a Field Notebook in it for on-the-go intermittent journaling. It fits in my back pocket, It is simple and unobtrusive. It doesn't make me look like too much of a geek.

[Photos included at original response]