I'm sure I've mentioned this before: I would love to simplify the D&D game by adding resource cards that the players can retain or surrender as their possessions ebb and flow.
Magic Realm uses a combination of chits (cardboard counters) and treasure cards to track each characters' possessions and abilities. These chits and cards are designed specifically for Magic Realm, and the effects of the treasure cards for that game are difficult to apply directly to D&D.
Each character in Magic Realm has a combination of 12 "chits": those represent the move, fight and magic abilites of that character. As an example of treasure cards in Magic Realm, there are 5 "gloves" treasures that essentially replace certain fight chits, making combat easier for a character that needs, uses, or could effectively use that fight chit. That Magic Realm treasure mechanic is somewhat difficult to port directly over to D&D, as the combat mechanic in D&D works quite differently.
While the Magic Realm treasure cards and chits themselves cannot be applied directly to D&D, the idea of items, abilities, and treasures can. In fact, D&D 4E has already done this, by producing the powers decks. Those are a little more complicated than I am looking for, but it demonstrates that the general principle can be applied quite easily.
Part of my difficulty in using existing equipment and magic item cards such as the Paizo offerings is that the range of cards is somewhat limited. While there are armor, treasure and equipment cards, there are other resources that are not represented by those cards.
You see, as I thought about the sorts of resources that could be modelled in card form, my list started to get quite long. In addition to the items available in the Paizo deck, I wanted to add such things as gems, jewelry, lodgings, clues, rumors, spells, hirelings, abilities, and languages. Some of these elements could be found in the Magic: The Gathering cardgame (I found lightning, fireball, sleep, and some other spells in M:TG), but other spells had no M:TG equivalent.
As I mentioned earlier, I came to the conclusion that I would have to design my own cards, if I wanted to cover the range of resources that I was considering, and if I wanted to have them at a size small enough that they would not take up an inordinate amount of space at the table.
My other consideration was cost. I wanted something that would be inexpensive, and easily replaceable, so that if a card was lost or soiled, the loss would be immaterial, and the card could be easily replaced.
I will post some pictures of the cards that I printed shortly.