Nice compiliation.

Levenger's pocket briefcase is pricey but very durable. I've had mine since probably 2010 and can't tell it's any more than a week old. Oxford makes a less expensive version called the At-Hand Note Card Case.

My EDC index card gizmo is a Levenger Jotlet, which is a 3x5 top-hinge Circa notebook. Of course, such things can be home grown with three Circa-equivalent discs, a punch, and stiff plastic.

Anything with Lochby on it is nice, too.