I've used one as a Hipster PDA case and general purpose wallet. You can get 12 cards into each section without too much trouble. I kept one pocket as a sort of portable inbox, one as a store for blanks, one as a general "stuff i might want to look at" reference, one for a portable pocket mod calendar. The last two were for stamps, mini post its, and forms of payment: cash, card, and a cheque.

I've now decided that in most cases, a stack of cards clipped together makes a better PDA. The memo pocket is bulky... keeping it in your jeans pocket looks suspicious and feels awkward when you sit down. I use my hipster now so that one side of the stack contains the things I need to refer to most often (usually my next actions is on top, but sometimes an agenda card or something). The other is always a blank or partially blank writing surface.

I still carry the memo pocket but it tends to stay on my desk or in my coat or bag. My hipster is always about my person.

The pocket is pretty rugged. It will probably bulge and bend a bit if you stuff it full of index cards, but I can't see any sign that it'll fall apart.