I've seen these in the stores and thought I'd give one a try. I started by attempting to transfer the contents of my bi-fold, windowed, money-clip, front-pocket wallet:

* Three credit cards
* Two state issued ID cards
* Insurance card (credit card sized)
* Five store loyalty cards (credit card sized)
* School ID (in a sleeve with bus pass taped to outside)
* Two hotel room keys
* Five business cards
* Five bills of US cash

That did not even come close to fitting. Here's what I managed to get in comfortably:

* Three credit cards
* Two state issued ID cards
* Insurance card (credit card sized)
* Five store loyalty cards (credit card sized)
* One hotel room key

Adding one more item caused the case not to seal entirely. Adding two more made it hard to close (and reopen). Adding three more made it impossible to close.

Here are the major negatives:

* US Cash needs to be folded into thirds or quarters to fit. That makes the cash very thick. If I take out three cards, I can get the cash in.
* Student ID with sleeve did not fit at all. It was just too big. I may be able to trim the sleeve a little with a pen-knife, but that's a pain.

Fortunately, this thing is pretty inexpensive. I'll try to go through the stack and see what I can take out.

Update: After using it for a couple days, I added a star! What is really cool about this wallet is that it opens like an expanding filing system. You can easily get to any individual card inside. I find it's easier to fumble around to get my hotel room key card out with my hands full than my old wallet.